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PALEOMANIA the Great International Fossil Collection

PALEOMANIA the Great International Fossil Collection

The International Museum Institute of New York

presents

PALEOMANIA The Great International Collection

Drawn from the world’s foremost fossil collections, the unprecedented treasury of fossil casts known as PALEOMANIA brings together into one exhibition some of the most exciting finds in the history of from over a century of worldwide excavations, exhibited as sculptural works of art.

Spanning 4.6 billion years in scope, from the earliest invertebrate marine life through the , , and to and prehistoric , this internationally acclaimed, comprehensive collection dramatically illustrates the awesome story of prehistoric life on Earth.

Displaying casts of rare from the Americas, Europe, Asia, , and Australia, this prestigious collection includes skeletons, skulls, claws, and eggs gathered from such revered museums as the Smithsonian Institution, the American Museum of Natural History, The Royal Ontario Museum, and the Carnegie Museum, as well as many others.

This famed traveling exhibition is now available direct from its celebrated showings at the World Trade Centers in Boston, San Juan, and Taichung, the Fernbank Museum of Natural History in Atlanta, the Discovery Center at Colorado National Monument, and the Natural History Museum of El Paso, where it was admired by millions of people. These compelling natural artifacts, rarely seen outside of their respective museums, are on view together exclusively in PALEOMANIA and its touring collections.

Contact: Albert Acosta, Curator International Museum Institute of New York 315.396.0541 [email protected]

PALEOMANIA The Great International Fossil Collection is proud to include casts of important fossils housed in the following venerable collections

UNITED STATES EUROPE AND GREAT BRITAIN

National Museum of Natural History Musee de l’Homme (Smithsonian Institution) University of Bonn American Museum of Natural History Humboldt Museum Carnegie Museum Bavarian State Institute of Natural History Museum of Geology and Palaeontology Los Angeles County Vienna Natural History Museum University of California, Berkeley Swedish Museum of Natural history University of California, Los Angeles British Museum of Natural History Brigham Young University Royal Scottish museum University of Texas, Austin University of Nebraska State Museum ASIA ~ AUSTRALIA ~ AND THE Harvard University MIDDLE EAST Peabody Museum, Yale University Monroe Community College Beijing Institute of Page Museum Paleontology and Paleoanthropology Alf Museum University of Adelaide Museum of the Rockies Geological Survey of Pakistan

AFRICA CANADA National Museum Royal Ontario Museum South African Museum Royal Tyrrell Museum of Transvaal Museum Paleontology National Museum of Tanzania National Museum of Natural Science Cairo Geological Museum National Museum of Ethiopia

PALEOMANIA The Great International Fossil Collection IS GRATEFUL TO THE FOLLOWING DISTINGUISHED SCIENTISTS:

ROBERT T. BAKKER LOWELL DINGUS STEPHEN JAY GOULD TOM GRAY JOHN R. HORNER NICHOLAS HOTTON DONALD JOHANSON JOHN KAPPELMAN WANN LANGSTON JAMES H. MADSEN, JR. JOHN MAISEY WADE MILLER WILLIAM R. MUEHLBERGER JOHN OSTROM TIMOTHY ROWE DALE RUSSELL J. WILLIAM SCHOPF SMILJANA MIMA STOJANOVIC

PRAISE FOR PALEOMANIA

“After 65 million years, they’re back. In a BIG way.” BOSTON HERALD

“Now underway at the World Trade Center in Boston…the entire story of life on Earth as represented by the fossil record.” THE TAUTON GAZETTE

“This fascinating presentation…has educated and enthralled all who have been fortunate enough to view it.” MASSACHUSETTS GOVERNOR WILLIAM F. WELD

“The only exhibit of its kind in the world… Paleomania makes no bones about theatrical approach… when it comes to drama, intrigue and excitement, it’s tough to beat the theater of life.” AUSTIN AMERICAN STATESMAN

“A window with a view into the most remote prehistory of man and …the unique feature of Paleomania is that the casts are displayed as sculpture…quite different from the paleontological exhibits one usually sees in museums…response from the public continues to be surprise and pleasure from lay people and scientists alike.” HILL COUNTRY LIVING

“To see the originals you would have to travel all over the world…an unprecedented collection of dinosaur fossil casts!” DISTINCT MAGAZINE

“A new breed of both art and science…it’s amazing to see…” WESTLAKE PICAYUNE

“It’s thrilling to see children get an idea of how really big…some of these creatures were…wonderful creations, almost works of art, because that’s what they look like at first glance.” HILL COUNTRY NEWS

“Without a doubt, this exhibit provides unmatched educational opportunities for its visitors. Children and adults alike have a unique chance to learn about the history and development of life on our planet, and to place themselves within the awesome scope of that development…a testament to what can be accomplished when the public and private entities work together for the benefit of everyone.” TEXAS GOVERNOR ANN RICHARDS

“This collection contains some very important finds which have added tremendously to our knowledge…From June until the Labor Day weekend, 200,000 people visited Atlanta’s Fernbank Museum of Natural History to view the highly acclaimed collection… such a remarkable presentation… so readily accessible.” GEORGIA GOVERNOR ZELL MILLER

PALEOMANIA 4.6 billion years of fossil history

Eskimo Nebula (NGC 2392 NASA Hubble photograph)

“Whenever I look at a bone, I always see the fingerprints of the god who amused himself with sculpting it.” Pablo Picasso

As art sometimes reflects nature, so, in turn, does nature occasionally reflect art. These bones, and teeth, and talons tell a story. A story of living molecules beginning to reproduce themselves in an ancient sea and gradually crawling out onto dry land. A story of dynasties of giant, complex creatures dominating land, sea and sky, descended from the tiniest and simplest of ancestors in an incredible chain of reproduction and diversification. A story of strength, ferocity and gentleness in titanic proportions, in other words, the story of the ingenious adaptability of life in the face of death. For in this struggle we see dramatic evidence of nature’s unrelentingly exploratory forces at work. Viewed as a progression of sculptures, one could say that a distinct style emerges early and gradually refines itself over millions of years, sometimes simple, sometimes quite baroque, and usually astonishingly practical. A story without words, cleft by humankind from stone.

THE ERA warm, shallow, offshore environments from 4.6 billion to 570 million years ago where complex living organisms first arose.

During the first 3 billion years of the 1. Kingdom Monera, planet’s existence there was no ozone layer Phylum Cyanophyta in the atmosphere to shield the land from the Collenia versiformis sun’s ultraviolet rays. Life on Earth began Early Precambrian, Minnesota in the dark ocean depths where these rays, destructive to the delicate DNA molecules The oldest known visible structures that are exclusive to living organisms, could produced by living organisms, not penetrate. The early self-reproducing (“Cushion Stones”) are the fossilized one-celled organisms, known as remains of slimy mounds or mats formed by prokaryotes, were so primitive that they did the cementing (in distinctive layers) of not possess a distinct cell nucleus. About a calcium carbonate sediments to the filmy, billion years ago, these simple asexual cells gelatinous secretions of , also gave rise to the more complex eucaryotes known as blue-green algae. Appearing in which possess a cell nucleus along with the the fossil record 2.5 billion years ago, these capacity for sexual reproduction, which primordial colonies of photosynthetic allowed for the exchange of genetic material microorganisms formed great reefs in the and, as a result, evolutionary variability warmer lakes and shallow seas of the between organisms. Precambrian. This sliced cross-section of the 2 billion-year-old Collenia As some of these early microorganisms reveals an algae formation twisted by floods began producing oxygen, the oceans and the or volcanic activity. Private collection. atmosphere gradually became abundant with it. A reaction between lightning and the 2. Kingdom Monera, oxygen in the atmosphere slowly produced a Phylum Cyanophyta layer of ozone gas which, in turn, gradually Collenia tubiformis began to filter out enough of the harmful Late Precambrian, Montana ultraviolet rays to permit habitation of the shallower waters and, subsequently, the THE EDIACARA FAUNA land. Scattered throughout the world, the first In Western Australia the fossilized remains isolated communities of multicellular of simple microorganisms (such as ) life in the oldest inhabited seas appear to have been found in rocks that are close to have developed around the oxygen enriched 3.5 billion years old. This was the Archean oases of algal colonies from 700 to 600 Era, also known as the Precambrian period, million years ago. Discovered in the which lasted until about 570 million years Ediacara Hills of Southern Australia by Sir ago. The earliest organisms visible to the Reginald Sprigg in 1947 and known as the naked eye did not appear until about 700 Ediacara fauna, these rare Precambrian life million years ago. During the Late forms are the most primitive known. With Precambrian, the formation of cells organized into actual tissue and Gondwanaland united the modern continents equipped with rudimentary vascular of the Southern Hemisphere, providing systems, they probably absorbed oxygen through their skin, tending to prevent their becoming too thickly-tissued, unlike any poisonous stinging cells capable of animals that have succeeded them. paralyzing prey on contact. Among the oldest and most primitive of such creatures Evidence of glaciations and a meteorite are the primordial medusa (or jellyfish) of impact correspond to the disappearance of the Precambrian, whose colorful modern this fauna from the fossil record, separating descendants are virtually unchanged. the Precambrian Era from that of the Although their soft structures consisted Paleozoic. Although these early animal mainly of water, some ancient jellyfish such prototypes did not survive into the as Rugoconites (the oldest known true Paleozoic, they appear to have produced a medusoid jellyfish) were durable enough to variety of survivors including segmented fossilize after washing onto the beach and annelid worms (the presumed ancestors of drying in the sun. Remarkably preserved, the ), as well as the cnidarians this ancient impression is more than half a (jellyfish), and (the presumed billion years old. ancestors of the ). The red coloration of the rocks containing the 4. Phylum Cnidaria, imprints of these dawn animals is attributed Class Cubozoa to the oxidation of iron in the sand of the Kimberella guadrata ancient tidal flats as a result of the growing Late Precambrian, South Australia abundance of the corrosive gas in the atmosphere. From the Late Precambrian Ediacaran deposits of Flinders Range, South Australia. University of Adelaide.

3. Kingdom Animalia, Phylum Cnidaria Rugoconites tenuriugosus Late Precambrian, South Australia

Beginning life as a tiny polyp attached to the underside of a rock, followed by metamorphosis into a medusa, this Among the first metazoans to arise from archetypic cubozoan (preserved in side protozoan ancestry were the coelenterates view) possessed an elongate, square-edged (“Hollow Entrails”), or cnidarians. From umbrella. Commonly known as sea-wasps, sea anemones and corals to jellyfish, these this extant form of deadly, long-tentacled marine organisms are known for their great jellyfish is the most venomous predator on beauty and diversity. As with modern Earth, capable of inflicting instantaneous forms, many primitive varieties possessed death. 5. Phylum Cniadria, 7. Phylum Annelida, Class Scyphozoa Class Polychaeta Ediacaria Flindersi Spriggina floundersi Late Precambrian, South Australia Late Precambrian, South Australia

Well-documented in the fossil record, Sprigginia attests to the diversity of the early annelids, whose descendants Long regarded as one of the earliest (including earthworms and leeches) are still jellyfishes, the well-documented Ediacaria alive today. A flattened, segmented marine may have lived a sedentary existence on the worm, the extraordinary preservation of sea floor with its short tentacles extended most Spriggina specimens reveals a small, upwards, an assumption resulting from the muscular creature with relatively simple discovery of an anemone-like orifice on nervous and excretory systems. Owing to some Ediacaria specimens. the enlargement of its head and other physical similarities, it has been suggested 6. Kingdom Animalia, that his annelid may have been ancestral to Phylum Annelida the . Dickinsonia costata Late Precambrian, South Australia 8. Kingdom Animalia, Phylum Echinodermata Tribrachidium heraldicum Late Precambrian, South Australia

A bizarrely flattened and discoidal segmented marine work indigenous to the primordial tidal flats of southern Australia, Dickinsonia was usually quite small, although on occasion some grew to Representing the echinoderms in the extraordinary lengths. Already a diverse Precambrian community is the tiny, coin- group by the end of the Precambrian, the shaped fossil known as Tribrachidium, annelid worms presumably gave rise to the though it is such a primitive form that it segmented arthropods. exhibits only 3 of the 5 symmetrical body sections that distinguish true echinoderms such as starfish, sea urchins, and . Within this group, the origin of the chordates, the soft-spined ancestors of the , is theorized to have occurred. If Tribrachidium is an , then it may be evidence of the presence of the ancestors of the vertebrates in the oldest known seas.

9. Phylum Cnidaria, Class Anthozoa Charniodiscus opositus Late Precambrian, South Australia

Sea pens, or Pennatulaceans, are soft corals that live a benthic existence attached to the sea floor. Those of the earliest inhabited seas were large, frondosa structures that lived by filtering tiny particles of food from the warm waters of the shallow tidal flats.

11. Phylum Cnidaria, Order Pennatulacea Glaessnerina grandis Late Precambrian, South Australia

Rising like delicate seaweed plumes from the bulbous holdfasts anchoring them to the substrate and swaying with the gentle currents, Pennatulaceans resembling Charniodiscus were widespread throughout the world, from Newfoundland to England and Australia. This group exhibits distinguishing characteristics that still persist in living Pennatulaceans.

10. Phylum Cnidaria, Order Pennatulacea Charniodiscus arboreus Late Precambrian, South Australia

The last of such featherlike creatures to be Ordovices, whose farms were built on rocks found in the Late Ediacaran deposits, rich in fossils. Glaessnerina was the nearest to modern forms of sea pens. Because conditions Following the , rich formations favorable to fossilization persisted past the found along the border of Wales and point of Glaessnerina’s disappearance from England derive their name from the savage the Precambrian deposits, it is assumed that tribe of Silures that inhabited the region they declined to the point of . during the Roman occupation. Throughout the (435 million years ago), plants 12. Phylum Cnidaria, and insects invaded the land. In the Order Pennatulacea (395 million years ago), Cyclomedusa davidi characterized by fossils first discovered in Late Precambrian, South Australia Devon, England, advanced lobe-finned and tetrapod amphibians appeared in the freshwater streams of the newly formed Old Red Sandstone Continent which united Greenland with Europe and North America. At the close of both the Ordovician and Devonian periods, Gondwanaland drifted over the south pole, triggering the onset of glacial episodes accompanied by mass of marine life. Long regarded as ancestral jellyfish, the discoidal Cyclomedusae are now considered 13. Phylum Arthropoda, by the Australian scientists who have OrderAgnostida studied them for years to have been the Ptychagnostus holdfasts of other animals that lived attached Middle , Utah to the substrate, the sea pens.

THE EARLY TO MIDDLE PALEOZOIC ERA from 570 million to 345 million years ago

Known as the , about 570 million years ago dense populations of complex sea creatures suddenly appeared, marking the beginning of the Cambrian period and of the Paleozoic era. First Already well-established by the dawn of the discovered in northern Wales (once known Cambrian, this ancient order of minuscule, as Cambria), fossils of this period document ancestral trilobites must have evolved in the the early establishment of all modern animal primordial seas of the Precambrian. phyla, followed by the emergence of Although most agnostids (“Unaware Ones”) primitive, jawless fish in the Ordovician were not equipped with eyes, these early (500 million years ago), named for an creatures, less than half an inch in size, ancient Celtic tribe of western Wales, the persisted for some 135 million years. Ptychagnostus (“Folded Unaware One”), characterized by their minute size, lack of resemble the simplest living invertebrate eyes and greatly reduced thoracic (mid- chordates, the acorn worms which live along section) segments, lived a planktonic, the geothermal vents at the bottom of the drifting lifestyle in dark, murky marine sea. Private collection. environments which apparently were not conducive to vision. They became extinct 15. Kingdom Monera, around the close of the Ordovician. Private Phylum Cyanophta collection. Cryptozoon proliferum Late Cambrian, New York 14. Phylum Echinodermata, Class Eocrinoidea Gogia Kitchnerensis Middle Cambrian, Utah

Providing a variety of habitats for the sudden explosion of invertebrate life throughout the planet at the dawn of the Appearing in the Early Cambrian and Cambrian, the stromatolite reefs all but exhibiting the pentameral symmetry vanished about 570 million years ago, characteristic of echinoderms (the group presumably as a result of widespread which includes starfish and sea-urchins), the grazing on the algae that formed them. eocrinoids (“Dawn Crinoids”) of the shallow Although fossilized algae is distributed Cambrian seas were bottom-dwelling, bud- throughout the world, exceedingly rare, shaped creatures on elongated, tapering living stromatolites are found only in such stems. Lacking the specialized respiratory isolated places as the Bahamas and Australia structures of their more advanced where the currents are too swift or the descendants, these primitive marine animals waters to hypersaline to permit grazing. fed by transporting tiny, filtered food Exposed by glacial activity, this spectacular particles along their simple brachioles form of Cryptozoon (“Secret Life”) grew (arms) to their mouths, which were located along the barrier reefs of an ancient island on top of the bud, or theca. Although quite now known as the Adirondack Mountains. rare, they persisted for over 200 million Monroe Community College. years, disappearing after the Silurian. THE BURGESS FAUNA The origin of the first chordates (ancestors of the vertebrates) appears to have occurred Discovered by Charles Doolittle Walcott in within the early echinoderm group, some of 1909, the Middle Cambrian deposits of the whose free-swimming larvae closely of British Columbia represent the period of abundant genetic diffusion Preserved in exceedingly rare condition, which followed the initial explosion of with its soft-tissued antennae and limbs rapidly diversifying animal forms at the intact, including gills and chewing bases, dawn of the Cambrian. These extraordinary this small but widespread denizen of the “shadow fossils”, known as the Burgess ancient reef habitats is one of the oldest and fauna, are the filmy remains of creatures that best-known of the early spined trilobites. were buried alive about 530 million years Belonging to the corynexochid order, ago by a series of mudslides at the base of a was characterized by eyes of massive algal reef, leaving an unparalleled medium size with a (tail) of record of the soft-bodied animal life smaller size than its cephalon (head). indigenous to a primordial sea that stretched Although its soft parts were protected by a from the Arctic Ocean to the Pacific of sturdy (which is periodically Southern California. Miraculously preserved shed as it grew), it was a passive and to the finest detail as reflective imprints of defenseless scavenger that lived by filtering carbonized film on black shale, these tiny particles of food from the muddy sea primitive marine organisms are startling floor. evidence of the presence of all existing animal phyla in the Middle Cambrian seas, 17. Phylum Arthropoda, alongside a number of extinct forms that Oder Limulavida defy classification in any known groups. Sidneyia inexpectans From the Middle Cambrian Burgess Shale of Middle Cambrian, British Columbia British Columbia. U.S. National Museum. Swimming by means of a tail fan resembling 16. Phylum Arthropoda, those of crustaceans, this predatory Class Trilobita exhibits the combined Olenoides serratus characteristics of distinct family groups Middle Cambrian, British Columbia which have subsequently diverged (chelicerates and crustaceans). It fed by passing food from its rear limbs to its mouth, as do most marine arthropods, whose legs are outfitted with spiny teeth. The digested remains of tiny trilobites have been found in the guts of some specimens.

18. Kingdom Animalia, Phylum Chordata Pikaia gracilens Middle Cambrian, British Columbia

The unlikely preservation of this tiny marine sponges. Throughout the Silurian and organism supplies one of the most important Devonian periods, as predatory eurypterid, clues to the enigmatic origin of the early jawed fish, and amphibians appeared vertebrates. Despite its long standing and proliferated, the numbers of trilobites classification as an annelid worm, its dwindled, disappearing entirely at the close profound reinterpretation in 1979 by Simon of the Paleozoic Era some 245 million years Conway Morris and Harry Whittington ago. revealed the distinguishing bands of muscles and dorsal notochord extending the length of These vastly diversified primordial its body which identify this swimming invertebrates, exhibited in chronological filtrator-feeder of the shallow seas as the progression, comprise 8 distinct orders oldest known , a direct ancestor of (including the ) and represent the vertebrates. Outnumbered by vast every period of the Paleozoic Era from their varieties of arthropods and coelenterates, the sudden appearance in the Early Cambrian to first proto- appear to have been their extinction in the . From represented exclusively by this single private collections. in the Cambrian seas of western Canada where this rare and important 20. Order , creature (along with its myriad descendants) Family once faced a very tenuous future in terms of bristolensis survival. Early Cambrian, California

19. Kingdom animalia, Pylum Arthropoda Waptia fieldensis Middle Cambrian, British Columbia

Although superficially shrimplike, this primordial marine creature is ranked among the unplaceable early arthropods of unique anatomical form. Among the most common of the Burgess arthropods and dwelling almost exclusively on the shallow sea floor where it extracted small particles of food from the muddy sediment, it was probably a An early member of the olenellid family, weak swimmer and did not actively pursue representative of the redlichiid order, with prey. large, crescent-shaped eyes. Among the oldest and most primitive of trilobites, a TRILOBITES spined, bottom-dwelling scavenger capable of both swimming and crawling. The most commonly preserved creatures of the ancient Cambrian seas were the 21. Class Trilobita, ubiquitous trilobites (“Three Lobes”). Order Comprising more than half of all known Olenoides superbus animal life at the time they shared the Middle Cambrian, Utah warmer waters with early jellyfish and

A late representative of the dwindling corynexochids which died out by the close A common representative of the widespread of the Cambrian, characterized by its corynexochid order, characterized by its medium-sized eyes and spiny pleura (ribs). medium-sized eyes and enlarged pygidium A scavenger adapted for crawling on the (tail). muddy sea floor.

22. Order Corynexochida, 24. Class Trilobita, Family Ogygopsidae Order Odontopleurida Hemirhodon amphipyge Eoceraurus trapezoidalis Middle Cambrian, Utah Ordovician, Oklahoma

The spines of these peculiar trilobites were A member of the ogygopsid family, a special adaptations for the widest possible variant form of corynexochid, characterized distribution of body weight on the soft sea by medium-sized eyes and a broad, fused floor, where its life was spent crawling in pygidium, well-developed for burrowing. the mud. From the Orodovician of Oklahoma. Excellently preserved along 23. Class Trilobita, with the partial remains of a juvenile of the Order Corynexochida same species, this rare, early phacopid walcottana belonged to a diverse new order Late Cambrian, Pennsylvania distinguished by its highly complex eyes. 25. Class Trilobita, 27. Order , Family Raphiophoridae Family Trinucleidae mcgeheei laelus Ordovician, Oklahoma Ordovician, Pennsylvania

An elegant, pyritized example of the vast order of ptychopariids, this tiny, sightless member of the widespread trinucleid family This unusual and highly specialized member possessed a broad, perforated brim along the of the raphiophorid family was a sightless, cephalon (head) and elongated genal spines, lightly built swimmer, protected from which supported its body on the soft, muddy predators by its long spines which also may sea floor on which it lived. have aided in surface flotation and drifting with the current. 28. Order , Family 26. Class Trilobita, Kanoshia kanoshensis Order Ptychopariida Late Ordovician, Utah Amphyxina bellatula Ordovician, Missouri

Tiny, gregarious examples of the A typical example of behavior, this ptychopariids, an extremely diverse order early form of phacopid, ancestral to the later which gave rise to most of the trilobites that dalmanitid family and distinguished by its appeared after the Cambrian, descended distinctively flared pygidium, commonly from the older, extinct redlichiids, which protected itself from danger by rolling up their earliest representatives resembled. when threatened. 29. Class Trilobita, 31. Order Phacpida, Order Family Fragiscutum glebalis Diacalymene clavicula Silurian, Oklahoma Silurian, Oklahoma

A tiny and uniquely specialized member of the longstanding proetid order, capable of enrolling and distinguished by its unusual A member of the abundant calydmenid eyes positioned at the ends of short stalks. family, a variant form of phacopid with

smaller, simpler eyes than its more 30. Class Trilobita, specialized relatives, and typically found Order enrolled. Arctinurus boltoni

Silurian, New York 32. Order Phacopida,

Family Dalmanitidae Huntonia oklahomae Early Devonia, California

An unusually specialized phacopid, this

long-snouted member of the widespread A large and splendid example of the diverse dalmanitid family was well-adapted for order of lichids, a broad, flattened form well plowing in the sand and burrowing, lying suited for a life spent crawling on the sea with only its head exposed, watching with floor, filtering organic food particles from its compound eyes and waiting for tiny prey the mud. to crawl or drift by.

33. Class Trilobita, 35. Order Proetida, Order Lichida Family Phillipsidae Dicramurus hamatus Breviphillipsia sampsonii Early Devonia, Oklahoma Mississippian, Missouri

A member of the diverse phillipsid family, representative of the far-ranging proetid This rare, exotic form of lichid was order which flourished from the Ordovician equipped with a pair of horns and elongate, to the end of the Paleozoic. prickly spines extending from every part of its body, an effective defense against the 36. Class Trilobita, growing number of marine predators. Order Proetida Ditomopyge parvulus 34. Class Trilobita, Pennsylvanian, Oklahoma Order Odontoplurida Leonaspis williamsii Early Devonian, Oklahoma

With tiny eyes positioned on the tips of short, stiff stalks, this small, bizarrely This cluster of tiny, pyritized proetids may barbed trilobite was among the last represent moltings rather than the actual representatives of the rather spiny order of remains of the animals themselves, which odontopleurids, which had persisted from periodically shed their as they the Late Cambrian. grew. 37. Class Trilobita, eyes and enlarged cephalons and pygidia, Order Proetida were simple scavengers, dwelling on the Delaria antiqua muddy sea bottoms and grubbing for food, Permian, Texas periodically shedding their sturdy exoskeletons as their softer internal parts outgrew them. A gentle and gregarious creature, Homotelus (“Same End”) derives its name from the similarity between its anterior and posterior sections. This spectacular cluster of 30 ptychoparlid trilobites perished together 500 million years ago in the ancient sea of Oklahoma, preserved in a mass burial along with cast- off moltings, in beautiful mosaic detail.

Private collection. Descended from the primitive ptychopariids of the Early Cambrian and characterized by 39. Class Trilobita, its large eyes and pygidium and the ability to Order Phacopida enroll, this late proetid was among the very last of the trilobites. Early Silurian, Tennessee

38. Phylum Arthropoda, Class Trilobita Homotelus bromidensis Ordovician, Oklahoma

Though some trilobites were sightless, most were equipped with either single-lens or compound eyes. With an almost hemispherical field of vision to aid them in their hunt for food on the muddy ocean bottoms, trilobites were the first creatures on Earth to develop complex eyes, some of which were composed of over 10,000 individual lenses.

Although compound eyes were not

uncommon among the diminished groups of Presumably evolved from segmented trilobites that survived the Ordovician Precambrian annelid worms, these primitive extinction, this progressive order of early arthropods, distinguished by their simple phacopids had eyes equipped with an advanced type of lens structure that enabled ferocious predator. Numerous fossilized them to see better in the deeper, darker trilobites bear scars left by the fearsome waters and at night. Inhabiting the offshore pincers of such creatures. marine environments of the Silurian, this rare and giant form of Dalmanites may have Descended from trilobites (whose enormous been nocturnal. Burrowing with its populations they helped to decrease), these diminutive telson (tail spike) into the soft impressive invertebrates possessed an sand until only their heads were exposed, elongated, segmented body and were they would lie in wait for tiny drifting prey. equipped with a pair of compound eyes as Private collection. well as a pair of simple ones. Sometimes growing to lengths of as much as 10 feet 40. Phylum Arthropoda, these early arthropods were the direct Class Erypterida antecedents of the first creatures to leave the Eurypterus remipes aquatic environment to inhabit dry land: the Eurypterus lacustris scorpions. Private collection. macrophthalmus Late Silurian, New York 41. Phylum Arthropoda, Class Arachnida Palaeoscorpius devonicus Late Devonian, Germany

Widespread throughout the Paleozoic Era, these giant water scorpions were particularly abundant during the Silurian Period (465 to 415 million years ago) when they ranged from marine environments to brackish streams and estuaries. The sharp telson, or tailspike of Eurypterus (“Wing Fin”), primarily useful for correcting its position when stranded upside down on the seafloor, may have been armed with a venomous stinger. Two individuals of one species and Among the very first creatures to abandon a smaller individual of another species are the aquatic environment and invade the land, dramatically preserved together with yet an event which took place during the Late another species of eurypterid prominent at Silurian, were the scorpions. Derived from the bottom of the slab. Armed with pincers eurypterid, the earliest true scorpions were and a spiked fantail Pterygotus was a marine creatures. Pressured by the rise of predatory fishes and eurypterids, the Ancestral to the first true fish, the appearance of amphibious scorpions, (“Jawless Ones”) are the oldest fossil capable of surviving in a terrestrial vertebrates. Of this early group of marine environment for limited visits, presumably and freshwater creatures, Cephalaspis led to the establishment of completely (“Shield Head”} was the most successful terrestrial, air breathing varieties. and enduring. Ranging throughout the Late Silurian rivers, lakes, and estuaries from Related to spiders, these ferocious predatory Asia to Germany, it had spread as far as arachnids possess a venomous stinger on the eastern Canada by the end of the Devonian. tip of the tail, with which they are capable of disabling their prey. Unlike the tiny, With its head encased in a bony, armored primitive Silurian scorpions, the amphibious carapace (or shell), Cephalaspis was Devonian forms were adapted to feeding out vulnerable to very few predators other than of water. External digestion, or liquid eurypterid. Presumably a bottom dweller, it feeding, is not possible in an aquatic fed by filtering particles of food from mud environment, where ingestion of solid food sucked into its small, jawless mouth. is necessary. The Devonian scorpions Between its 2 upward-looking eyes lay the exhibit a definite landward trend along the pineal body, or “Third eye,” a photosensitive deltas and intertidal estuaries of central organ which distinguished light from shade. Europe with the sole exception of Networks of nerves, preserved in a number Palaeoscorpius, a formidably large example of fossil specimens, extended from its known exclusively from deep marine simple brain to sensory dorsal plates. Once deposits. From the University of Bonn. considered to be electrical organs, these sensitive plates probably served to monitor 42. Superclass Agnatha, such things as temperature and water Order pressure as well as vibrations. They became Cephalaspis Lyelli extinct some 365 million years ago. From Early Devonian, Scotland the Royal Scottish Museum.

43. Class Trilobita, Order Phacpida africanus Devonian, Morocco

Although trilobites began to decline after the close of the Cambrian, probably as a result of increased predation from the rapidly for hunting and feeding. Their paired and growing numbers of fish and other marine spiny pectoral appendages may have served life, they enjoyed a temporary resurgence of as anchors against currents as they gleaned diversity in the Devonian, giving rise to the for food on the muddy river bottoms. The 2 largest and most grotesque forms known. In pockets stemming from the throat may have dwindling numbers, these once common served as lungs, temporarily allowing creatures survived into the Permian before to breathe air when stranded on vanishing from the fossil record. This giant shoals by the tide. This exquisitely phacopid trilobite, with its excellently preserved school of placoderms represents preserved compound eyes, each composed some of the earliest of true fish. American of over 100 individual lenses, is Museum of Natural History. characterized by its large eyes, a granularly decorated glabella (face), and the ability to 45. Class , enroll. Private collection. Order Dunkleosteus terrelli 44. Class Placodermi, Devonian, Ohio Order Bothriolepis canadensis Late Devonian, Canada

Derived from the earlier Agnatha, the The earliest known giant vertebrate, Devonian placoderms were among the first Dunkleosteus (“Dunkel’s Bones”) grew to ancestral fish to develop jawbones and lengths of over 16 feet and weighed up to 5 paired fins. Growing to about 1 foot in tons. Like all placoderms, its massive head length, these primitive vertebrates were was protected by an armor of bony plates equipped with a bony armored carapace while its scaly trunk was exposed. which covered the front part of the body, the Possessing no teeth, its powerful jaws were exposed trunk and tail presumably covered equipped with razor-sharp blades of bone with scales. Also found in , the which enabled it to slash and crush the widespread Bothriolepis (“Trench Scale”) armor of its prey. Also known as reached North America near the end of the Dinichthyes, this monstrous fish hunted Devonian, inhabiting freshwater lakes and everything from sharks and other streams. placoderms to large invertebrates throughout the Devonian oceans of North America and The development of jaws in these fish, Europe. Their extinction coincides with though rudimentary, increased their capacity evidence of widespread tidal waves which appear to have devastated the majority of this ruggedly adaptive crossopterygian fish marine life along the seashores at the end of gave rise to tetrapod amphibians, the others, the Devonian period about 365 million years to saltwater coelacanths. The apparent ago. Private collection. progenitor of all terrestrial vertebrates, it was extinct by the dawn of the Permian. 46. Order Crossopterygii, Royal Ontario Museum. Suborder Thipidistia Eusthenopteron foordi 47. Class Amphibia, Late Devonian, Canada Subclass Labyrinthodontia Ichthyostega Late Devonian, Greenland

As the Late Devonian freshwater streams and ponds shrank or dried up during periods of drought, the primordial, lobe-finned lungfish of the period developed rudimentary adaptations to the hostile environment of land before spreading into the seas. Special bone features that enabled them to crawl on their fins evolved not for the purpose of escaping the aquatic environment, but as a means of reaching fresher water when shrinking pools became crowded and putrid or the streams became The origin of terrestrial vertebrate life appears to have begun in Greenland with the too muddy. appearance of the first tetrapod amphibians. A formidable predator resembling the Among the earliest of these creatures, modern pike and perfectly preserved with its Ichthyostega (“Fish Plate”) inhabited fins and scales intact, this elongated freshwater lakes and streams during the Late freshwater fish was highly adapted to the Devonian and Early . Derived severe climatic fluctuations (often daily) of from crossopterygian fish, this air-breathing the Devonian. With tear ducts to keep its predator still retained many of the primitive eyes moist and lungs derived from a simple fishlike structures of its ancestors. Although air bladder originally employed to keep the it possessed scales and a long tail fin, it also bodies of fish right side up, Eusthenopteron had a sturdy backbone and 4 short limbs, (“Good Strong Fin”) was able to breathe out each equipped with 7 digits, enabling it to of the water during times of drought and waddle about on dry land for limited periods of time before having to return to water. stagnation while other fish suffered asphyxiation. Some of the descendants of Unlike the amphibians that were to follow, Ichthyostega lacked notches for ears, an indication that it had no auditory sense. Its the Paleozoic Era was of such massive direct relation to crossopterygian fish is proportions that it has never been equaled, evidenced by their virtually identical over 90 percent of all species vanishing. patterns, a distinctive characteristic with The decimation of the once dominant ichthyostega passed on to the varied multitudes of -like provided generations of labyrinthodont amphibians an ecological niche that favored the which it produced. In fact, this important surviving groups. creature is believed to have given rise to all of the diverse and prolific groups of reptiles, 48. Paleozoic Sea Floor birds, and mammals which followed. Crinoids Although well-documented in the fossil Brachiopods record, Ichthyostega is known only from Coral incomplete remains. Skull reconstruction Trilobite courtesy of the Swedish Museum of Natural Trilobite trackway History. Mississippian, Indiana

THE LATE PALEOZOIC ERA from 345 to 250 million years ago

Inundated by the inland invasion of the seas throughout the Mississippian (345 million years ago), the first division of the Carboniferous period, immense tropical forest regions were fossilized into deep carbon bands in the Earth’s crust. During the Pennsylvanian (310 million years ago), the remaining division of the period, reptiles diverged from their amphibious ancestors and began to proliferate on the land.

By the Permian (280 million years ago), named for the discovery of fossils near the region of Perm in Western Siberia, mammal-like reptiles (synapsids) had Dominated by a fossilized and appeared, characterized by developments flecked with tiny brachiopod shells, coral, that would ultimately distinguish them from and even a half-buried trilobite, this their reptile ancestors and lead to a new exquisite slab has preserved a cross-section class of animals. of a once thriving marine ecosystem.

All of the continental land masses of the Trace fossils preserving the activities of Cambrian collided during the Permian, trilobites are not uncommon. Digging forming the supercontinent of Pangaea. A furrows into the sand with their jointed series of devastating ice ages were triggered limbs (or endopodites), many left tiny trails by the encroachment of the supercontinent that dried and hardened before they could be on both poles. The resulting widespread washed away. Fossilized burrows indicate extinction that ended the Permian period and that trilobites apparently laid their eggs in pits carefully dug in the sea floor, afterwards 50. Phylum Cnidaria leaving them to be covered by drifting sand Class Scyphozoa to protect them from predators. These traces Essexella asherae of an ancient journey were left on the Pennsylvanian, Illinois shallow sea floor by a small marine arthropod. Private collection.

49. Phylum Echinodermata Class Crinoidea Ulrichcrinus coryphaeus Actinocrinites gibsoni Dorycrinus gouldi Taxodrinus coletti Sarocrinus nitidus Agaricocrinites americanus Late Mississippian, Indiana Swimming by rhythmic contractions of their gelatinous bodies, these medusoid jellyfish preyed on small creatures that became entangled in the poisonous, dangling tentacles. Lacking a central nervous system, these simple marine organisms are actually colonial animals composed of hundreds of specialized individual creatures, each fulfilling a separate function such as flotation, stinging, feeding, or digestion. From the famous Mazon Creek deposits. Private collection.

51. Kingdom Plantae, Class Lyginopteriodopsida Neuropteris rodgersi Pennsylvanian, Pennsylvania

The Early Paleozoic crinoid gardens were sparse compared to the vast varieties of the Mississippian period, known as the Age of Crinoids. Most of the crinoids died out at the close of the Paleozoic; however a few species still survive today. Preserved in beautiful detail, these 6 crinoid species were rendered in bouquet. Private collection.

Presumably evolved from Precambrian one- magnificently winged creatures as the celled algae, primitive plants existed long ancestral dragonflies with 30 inch before the appearance of the first animals. wingspans that subsequently inhabited the Neuropteris, an ancient seed fern of the coal coal swamps from the Pennsylvanian forests of 300 million years ago (derived throughout the Triassic. Distantly related to from early terrestrial plants of the primordial these ancient insects, Urogomphus (“Bolt Silurian period) was able to circulate water Tail”), a true dragonfly, was a formidable and nutrients to the cells of its highest leaves predator, using its spiny legs for capturing by means of its advanced root and vascular prey. From the Humboldt Museum. systems. Unlike the more primitive true ferns which reproduce from spores, these large, non-flowering, tree-like plants were 53. Class Insecta crowned with seed-bearing fronds. Order Orthoptera Mylacris Supported by rigid trunks that often reached Pennsylvanian, Kansas heights of as much as 10 feet, this common seed fern proliferated in the dense swamps and forests of the Late Paleozoic during a time when coastal areas were often inundated by the intermittent rising of the seas. Deeply buried under accumulated organic debris, the remains of these early plants did not decay but instead turned to peat which in time became coal. Private collection.

52. Phylum Arthropoda, Class Insecta Urogomphus giganteus Late Jurassic, Germany

The most successful group in the animal kingdom, insects proliferated with the spread of the Carboniferous forests. The development of folded wings from thoracic flaps enabled the more advanced varieties of the terrestrial arthropods to escape predation. Unlike the dragonflies, whose , outstretched wings made hiding from predators difficult, these newly evolved insects with wings that folded As evidenced by their distinctly segmented backwards rapidly flourished. bodies, insects are the direct descendants of the early aquatic arthropods. Appearing in Inhabiting the damp ground of humid, the Middle Devonian, primitive wingless swampy forests, some Pennsylvanian insects gradually gave rise to such cockroaches such as the gigantic Mylacris commonly grew to lengths of 3 to 4 inches. Unlike insects whose larval forms differ radically from their adult forms, cockroaches undergo incomplete metamorphosis, hatching into nymphs that differ very little from adult forms. Enduring for over 280 million years, cockroaches are close to the common ancestry of such diverse groups as crickets, beetles, wasps, ants, and moths. Private collection.

54. Class Reptilia, Order Cotylosauria With a sturdy, terrestrial-type skeleton Cephalerpeton ventriarmatum characteristic of reptiles and a skull Pennsylvanian, Illinois exhibiting prominent ear notches characteristic of amphibians, Seymouria was long regarded as a primitive reptile and the closest link to their amphibian ancestry. Because related forms document the passage of a gilled larval stage, a characteristic thoroughly eliminating them from the reptilian class, Seymouria is now placed among the anthracosaurs (“Coal Reptiles”) One of the very oldest vertebrates to be by most authorities, thus including this recognized as a reptile, Cephalerpeton distinctly terrestrial amphibian in the group belonged to the most primitive group, the of Permian labyrinthodont. Although anapsids, which began with the suborder Seymouria (named for the town of Seymour, Captorhinomorpha. Descended from Texas, where it was discovered) differed labyrinthodont amphibians, the early “stem very little from the Pennsylvanian ancestors reptiles”, or cotylosaurs, were the ancestral of the reptiles, it left no known descendants. stock of all Reptilia, distinguished by their This exquisite skeleton is from the U.S. revolutionary ability to deposit their eggs on National Museum. dry land, bypassing the gilled larval stage of their immediate ancestors. As the first 56. Class Amphibia, vertebrates to become entirely independent Subclass Labyrinthodontia of the water, their ability to exploit the Eryops megacephalus terrestrial habitat led to a rapid radiation of Early Permian, Texas diversely specialized reptile groups which included the ancestors of birds and Throughout the Carboniferous and Early mammals. From the Mazon Creek deposits. Permian periods, the evolving groups of Yale Peabody Museum. primitive amphibians, collectively known as labyrinthodont (due to the labyrinthine 55. Subclass Labyrinthodontia, wrinkles in their , derived from Order Anthracosauria their crossopterygian antecedents) are Seymouria baylorensis exemplified by Eryops (“Drawn Out Face”) Early Permian, Texas which inhabited the lush deltas along the edge of the ancient sea of Texas, Oklahoma, and New Mexico 260 million years ago. (“Two-Tail”), a flattened, bottom-dwelling Eryops was largely an aquatic creature like predator of the Late Pennsylvanian to Early the modern alligator. Unlike the early fish, Permian streams and ponds. Ranging from these amphibians were able to listen for their 1 to 3 feet in length and lying in wait in the prey due to their well-developed eardrums, murky bottom, Diplocaulus fed by evolved from degenerate skull bones ambushing its prey, its upward-looking eyes inherited from their fish ancestors. positioned on top of its grotesquely boomerang-shaped head.

A true amphibian, Eryops laid its eggs in water, its young passing through a larval stage, with gills for breathing, before reaching maturity. Armed against predators with bony nodules in its skin and growing to about 6 feet in length, this extremely common swamp creature presumably preyed on fish and other amphibians. Hunted, in turn, by the fierce Dimetrodon, Eryops was With tiny legs for its overall body length and extinct by the close of the Permian, although a body too flattened to bear the musculature its survivors gave rise to the peculiar necessary for swift locomotion, Diplocaulus stereospondyl amphibians of the Triassic. was probably not a very strong swimmer Collected by Kenneth W. Craddock. Private despite speculations regarding the collection. hydrodynamic properties of its oversized head. Unable to see each other except by 57. Class Amphibia, touch due to the placement of their eyes, the Subclass Lepospondyli widely extended corners of these creatures’ Diplocaulus magnicomis skulls may have provided advantages in Early Permian, Texas intimidating displays of head-butting during mating competition, gradually producing a Among the most bizarre of the Permian genetic favoring of those with the greatest lepospondyl amphibians is Diplocaulus range. Private collection. 58. Subclass Synapsida, they probably hid in the lush vegetation, Order Pelycosauria waiting for unsuspecting prey to stray too Dimetrodon limbatus close to escape a quick surprise attack. Early Permian, Texas The creature’s impressive dorsal “sail” provided a large surface area for warming the blood when exposed to sunlight and cooling it when in the shade, although such spectacular features may evolve more rapidly for the purpose of mating displays than for thermal functions. By the Middle Permian, when the climate along the delta became too dry to sustain them anymore, the Dimetrodons disappeared quite suddenly from the fossil record. Brigham Young University.

59. Class Reptilia, Subclass Synapsida Aerosaurus wellesi Early Permian, New Mexico

The aggressive, carnivorous Dimetrodon (“Dual Sized Tooth”), distinguished by a prominent dorsal fin along its back, prowled the upland regions of the swampy delta of northern Texas along the edge of a shallow, drifting sea. The dominant predator of this area, Dimetrodon fed without competition The most primitive of the early synapsid on an abundant population of large reptile groups, the pelycosaurs may have led defenseless amphibians. Belonging to the a somewhat amphibious existence, similar to archaic order of finback pelycosaurs, these that of alligators. Catching and killing its early cold-blooded synapsids were ancestral prey in jaws lined with an extraordinary to the mammal-like reptiles of later Permian number of sharp teeth, Aerosaurus (“Air times. Dimetrodon was equipped with a ”) was apparently an aggressive ferocious arcade of palatine teeth in addition predator. Equipped with an unusually long to the sharp teeth that lined their jaws. and flat swimming tail, this young Incapable of sustaining an extended chase, pelycosaur probably preyed on fish as well as on smaller, slower reptiles and adapted for swimming and appear to have amphibians. been web-footed.

Although undoubtedly cold-blooded, Although mesosaurs are believed by some to because of their specialized bone structure be a transitional stage between the later the archaic synapsid reptiles are considered ichthyosaurs and their early land-dwelling to be the ancestors of the therapsids, the ancestors, due to their extremely primitive later and more advanced reptile group that aquatic adaptation, there are no actual subsequently gave rise to warm-blooded affinities between the two animal groups to mammals. Some scientists have also noted support this supposition. Because the affinities between the Early Permian remains of this creature have been found pelycosaurs and the later Permian freshwater only in Brazil and South Africa, Mesosaurus mesosaurs, the possible forerunners of the is one of the very strong links in the chain of air-breathing, marine ichthyosaurs. evidence for shifting continents. University Collected by Charles Camp and Samuel of California, Los Angeles. Welles in 1928 and identified by Wann Langston and Robert Reisz in 1981, this 61. Class Reptilia cluster of Early Permian specimens also Subclass Therapsida contains the dissociated bones of various Dicynodon grimbeeki other reptiles and amphibians including an Middle to Late Permian, South Africa Eryops and an Edaphosaurus. University of California at Berkeley.

60. Class Reptilia, Subclass Anapsida Mesosaurus brasiliensis Early Permian, Brazil

For about 10 to 15 million years, great herds A small freshwater reptile of the lakes and of these fat, little mammal-like therapsids estuaries of Permian South Africa and South inhabited South Africa, Russia, Scotland, America (when the 2 continents were still Asia, and the Americas, apparently joined), the slender Mesosaurus (“Middle reproducing at an extraordinarily prolific Reptile”) grew to a length of 3 feet and had rate. Found in the red beds of the South jaws lined with needle-shaped teeth for African Karroo Formation, these 3 catching fish. The earliest known specimens are the remains of creatures that aquatically adapted animal descended from once flourished throughout a region that was terrestrial ancestors, its broad limbs were considerably closer to the South Pole during Permian times than it is now. In order to ”), which continued to appear in survive the severe Karroo winters, they may increasing varieties for the next 140 million have evolved some kind of furry insulation. years. The gradual breakup of Pangaea beginning at the end of the Triassic globally Although they were probably the first separated dinosaur populations along with successful group of herbivores among the the first true mammals, tiny burrowing vertebrates, equipped with horny beaks and descendants of the mammal-like reptiles. tusk-like upper canines, by the end of the Permian Period to the Middle Triassic, the 62. Class Reptilia, herds of Dicynodons (“Double Dog Tooth”) Subclass Archosauria had dwindled to extinction, survived by a Euparkeria capensis few relatives which evolved into early Early Triassic, South Africa mammals. From the famous Karro Formation. University of California, Berkeley.

THE TRIASSIC PERIOD from 230 million years to 195 million years ago

There were no flowers or grasses at the beginning of the Triassic Period (named for a tri-layered sequence of strata first discovered in southern Germany). Surrounded by a vast ocean, the supercontinent of Pangaea almost entirely circled the globe at the equator. Identical fossil remains found as far apart as Africa and North America suggest that the fauna of this period roamed freely across vast expanses of land that are now separated by the oceans. The Triassic marked the dawning of the Mesozoic (“Middle Life”) era, or the Age of Dinosaurs.

Because much of Pangaea lay along the equator, climates were generally tropical, Crowding the archaic Permian and warm, ferny swamps teemed with protomammals out of their dominant primitive amphibians and crocodiles. In the position in the competition for food, the arid desert regions, reptiles flourished with rapidly evolving Triassic reptiles known as the extinction of mammal-like reptiles, thecodonts (“Socket Tooth”) were producing the highly successful archosaur distinguished by the development of group which gave rise to crocodiles, remarkable open skulls, hollow bones that pterosaurs, and a new kind of animal were lightweight but very strong, and jaws gradually appearing in the Late Triassic lined with individually socketed teeth. This fossil record: the Dinosauria (“Terrible group of ancestral archosaurians (“Ruling Reptiles”) gave rise to the early saurischians and ornithischians of the Late Triassic (collectively known as the dinosaurs) as well as to crocodiles, birds, and the extinct flying reptiles. Exemplifying this important parent group, Euparkeria was a small creature that walked on 4 legs, but, like the modern crocodile, was capable of bipedal sprinting due to its powerful hind leg muscles. A predator whose advantage over its prey was its swiftness, Euparkeria was extremely between the eyes, the pineal opening, close to the immediate ancestry of the sensitive to light and shade, was used as a dinosaurs. This magnificent skeleton is “third eye” by early bottom-dwelling fish from the famous Karroo Formation. South and amphibians. Derived from an ancient African Museum. lineage of marine ancestors, the once photosensitive pineal body is still retained as 63. Class Reptilia, a vestigial organ within the brains of all Subclass Archosauria modern vertebrates. University of lunensis California, Berkeley. Triassic, Argentina 66. Dinosaur trackway The earliest known dinosaur, the “dawn Grallator raptor” preyed on insects and small 4-legged Late Triassic, Connecticut animals. Although it was an efficient, bipedal predator, its primitive jaws lacked the “hinged” flexibility of its carnivorous successors. The Argentine Museum of Natural Sciences.

64. Class Reptilia, Subclass Archosauria Herrerasaurus Triassic, Argentina

This early dinosaur was a primitive, bipedal Left in the mud by one of the earliest carnivore with a flexible jaw capable of dinosaurs, this footprint of an ancient entrapping its prey. Argentine Museum of Triassic coelurosaur (“Hollow-Tailed Natural Sciences. Lizard”) gives no hint of the gigantic proportions of its descendants which were to 65. Class Amphibia, follow. Ranging up to 10 feet in length, it Suborder Stereospondyla ran on its hind legs counterbalanced by a Hadrokkosaurus bradyi long tail. This little theropod (“Beast Late Triassic, Arizona Foot”), with its serpentine neck and lightweight, hollow bones, is believed to This large amphibian from the Moenkoepi have been swift and agile, chasing prey and Formation has the superficial appearance of tearing it with sharp claws and teeth. Such a large frog. The pronounced indentation behavior strongly suggests a warm-blooded metabolism, a theory popularized by the therapsid of the forest of Antarctica and the revolutionary paleontologist Robert Bakker. South African Karroo. Equipped with prominent canine teeth as well as other Among the first tracks to be found in North dental features characteristic of early America, they were discovered in the mammals, Thrinaxodon is widely regarded Connecticut Valley during the early 19th as the original stock from which they arose. Century by Edward Hitchock, who died Two skulls from the Karroo Formation. convinced that he had found evidence of University of California at Berkeley. prehistoric birds. When later compared to verified Coelophysis tracks, they proved to THE JURASSIC PERIOD be remarkably similar. Private collection. from 195 million to 140 million years ago

67. Order Therapsida, The Jurassic period, with its lush rainforests, Infraorder Cynodontia derives its name from an abundantly Thrinaxodon liorhinus fossiliferous sequence of chalky deposits Early Triassic, South Africa discovered in the Jura Mountains bordering Switzerland and France. For the 55 million year duration of the Jurassic period, the supercontinent of Pangaea was gradually being wrenched into 2 separate masses, Gondwanaland (Africa, South America, Australia, India, Arabia, and Antarctica) and Laurasia (Europe, Asia, Greenland, and North America). Among the survivors of the Triassic extinction, tiny primitive mammals began to diversify during the Early Jurassic.

By the dawning of the Late Jurassic (150

million years ago), the Atlantic Ocean had The transition from synapsid reptiles to formed and the drifting continents had mammals was gradual rather than a quantum barely begun to resemble their present leap. Replacing gorgonopsids as the shapes. Gigantic dinosaurs that cared for dominant predators of the Early Triassic, their young had evolved from their smaller cynodonts were small, fox-like creatures Late Triassic ancestors. Land bridges with fewer reptilian characteristics than their between the continents allowed the thriving ancestors. Although exhibiting tiny pits in herds of dinosaurs to migrate across great their skulls which appear to have held distances. Palm-like plants appeared and whiskers and possessing a palate separating flourished throughout the warm, swampy the nasal passages from the mouth, distinctly landscapes of the period, nourishing the mammalian features, the primitive reptilian largest creatures that ever walked the Earth. jaw structure of cynodonts retained certain prominent bones that became greatly 68. Suborder , reduced in mammals and incorporated into Infraorder Coelurosauria the inner ear. Extremely close to the longipes ancestry of the mammals, this group Late Jurassic, Germany included Thrinaxodon, an advanced of tissues as the carcass dried out prior to fossilization. From the famous lithographic limestone of Solnhofen. Bavarian State Institute for Paleontology and Historical Geography.

Of all the known fossils of adult dinosaurs, Compsognathus (“Elegant Jaw”) has the distinction of being the smallest. Running upright on its strong hind legs and stalking the underbrush for smaller Reptiles along the forested seashores of Jurassic Germany and France, Compsognathus was a swift and capable hunter, armed with sharp claws and teeth. This tiny coelurosaur was a relative of such giant creatures as the Tyrannosaurus 69-70. Class Aves, rex of a later age. More closely related to Subclass Archaeornithes Archaeopteryx (the bird-dinosaur), this Archaeopteryx lithographica skeleton shows that they shared a very Late Jurassic, Germany recent common ancestor, suggesting that birds may have inherited their warm- These small, feathered dinosaurs inhabited blooded metabolism from their dinosaur the Late Jurassic forests of Central Europe forebears. 150 million years ago. Although adapted for gliding and presumably for limited flight, The smaller bones exposed within the rib these primitive ancestral birds still retained cage of this well-known specimen have been efficient, grasping claws on each wing, as identified as the undigested skeleton of well as a long bony tail and jaws lined with Bavarisaurus, a tiny lizard that was sharp archosaurian teeth. Perhaps the most devoured just before the predator died. With famous fossil in the world, the spectacular its neck and tail bent backwards, this “Berlin specimen” was found in 1877. Compsognathus (discovered in 1861) was Owing to the faint preservation of its flight long thought to have died in agony, although feathers (overlooked for many years), the its posture is now attributed to the tightening juvenile specimen, known as the “Eichstatt specimen,” was long misidentified as a Compsognathus. These rare specimens are spectacular evidence of an intermediate stage between Reptiles and birds.

Roughly contemporary with the European Archaeopteryx, this feathered theropod dinosaur from Asia more closely resembled modern birds. Beijing Institute of Vertebrate Paleontology.

72. Superorder Archosauria, Suborder Pterosauria Rhamphorynchus gemmingi Late Jurassic, Germany

Because its remains have only been found in deposits of shallow marine lagoons rich in fossilized fish and squid, some believe Archaeopteryx (“Ancient Wing”) was capable of diving for aquatic prey. Others envision it darting along the ground bipedally, using its wings as spoilers to increase its speed while chasing insects and The first vertebrate creatures capable of small Reptiles or for soaring from tree to flight, the ancient pterosaurs (“Winged tree. From the famous lithographic Reptiles”) were not on the evolutionary path limestone of Solnhofen. Berlin specimen that led to birds. Descended from early from the Humboldt Museum. Juvenile Triassic archosaurs and divided into 2 specimen from the Jura Museum. distinct groups by certain physical characteristics, the older genera were 71. Class Aves distinguished by their long tails. Among the Subclass Archaeornithes most primitive, Rhamphorynchus (“Beak Cathayornis yandica Snout”) had a slender tail that ended in a Jurassic, China kite-shaped membrane which presumably served as a rudder. Growing to lengths of up to 2 feet, its average wingspan was about 4 feet. With an elongated, flexible neck and extended jaws lined with sharp, forward- Pterosaurs belong to the archosaur order, slanting teeth, this predator hunted along the which also includes dinosaurs and same reefs and shorelines as Pterodactylus. crocodiles. The first flying Reptiles to be Coiling its neck for diving and lunging at discovered, the raven-sized Pterodactylus, fish and squid, Rhamphorynchus speared its like all pterosaurs, was distinguished by its prey in the intermeshing barbs of its teeth, elongated fourth finger which supported a which allowed for no escape. powerful flight membrane. Their hollow, lightweight bones enabled them to venture Capable of sustained flight as well as aerial significant distances over the shallower acrobatics, Rhamphorynchus was probably waters of the ancient German seas, where a furry and warm-blooded. The leathery wing number of the remains have been recovered, membrane, extraordinarily preserved in this exquisitely preserved along with specimen, was reinforced with a lacing of impressions of their furry coats. special tissue. From the lithographic limestone of Solnhofen. Humboldt Once presumed to have been limited to Museum. gliding from high perches, they are now believed to have been thoroughly agile in 73. Superorder Archosauria, flight. They were quite vulnerable to marine Suborder Pterosauria predators, judging by the numerous Pterodactylus kochi pterosaur bones found in the stomachs of Late Jurassic, Germany ichthyosaurs. The long, narrow snout of Pterodactylus may have been an adaptation of probing in the sand for burrowing worms. From the lithographic limestone of Solnhofen, Humboldt Museum.

74. Superclass Chelicerata, Subclass Xiphosura Mesolimulus walchi Late Jurassic, Germany

Throughout the Jurassic, leathery-winged pterodactyls (“Wing Finger”) would have been a common sight gliding on the tropical Related to arachnids and the extinct breezes of the European coastal regions, eurypterids, the xiphosurans range from the catching up insects, small fish, and squid in Cambrian to the present. Derived from their long, sharply-toothed beaks. trilobites that had invaded estuaries and streams and lost their antennae (along with throughout adulthood, these dinosaurs other specialized modifications), they are (owing to their well-developed limbs) today represented by “living fossils” known apparently left their nests immediately upon as horseshoe crabs. Virtually unchanged hatching, probably feeding first on adult since the Permian, these arthropods dig feces, rich in fermentative bacteria, and later along the beaches for worms and other small progressing to plants and insects. As adults prey, often burying themselves in the sand. they fed on everything from plants to small reptiles and mammals. Possessing a pair of compound eyes (as well as a pair of simple ones) and equipped with a spiny telson for correcting its position when overturned, horseshoe crabs undergo periodic molting. Reflecting their ancient ancestry, in fetal form they resemble trilobites. During the spring mating season, males cling to the telsons of the females as they crawl along the sandy shores. Dramatic evidence of this same behavior in ancient forms is provided by the well-documented Jurassic Mesolimulus, whose trails sometimes lead to the remains of the “Nanosaurus” was renamed Othnielia in individuals that left them. From the 1977, on the centennial of its discovery by lithographic limestone of Solnhofen. Private the great pioneer paleontologist Othniel C. collection. Marsh. Featured in the 1993 Universal Studios film Jurassic Park, this 75. Order Ornithischia, spectacularly exposed in-situ skeleton is Family Hypsilophodontidae from the Morrison Formation of Emery Othnielia rex County, Utah. Brigham Young University. Late Jurassic, Utah 76. Subclass Ichthyopterygia, Possibly the smallest of the horny-beaked Order Ichthyosauria hypsilophodonts (“High Crest Tooth”) of Stenopterygius quadricissus late Jurassic Colorado and Utah, Othnielia, Jurassic, Germany formerly known as “Nanosaurus rex” (“Dwarf Lizard King”) only grew to a length of 3 to 4 feet. Agile sprinters when threatened or chasing prey, the omnivorous hypsilophodonts possibly flourished for longer than any other dinosaurs, about 100 million years.

After depositing their eggs in the sand, the females appear to have carefully manipulated them into spiral clutches of Flourishing throughout the Mesozoic, the regular depths and even spacing. Although ichthyosaurs (“Fish Reptiles”) appeared they probably remained with their herds during the Early Triassic. Growing up to 15 feet in length, they apparently evolved from land-dwelling creatures, possibly the Found in deposits rich in ichthyosaur pelycosaurs. From the limbs of their remains, these coprolites (“Dung Stones”) terrestrial ancestors, the ichthyosaurs are the fossilized excrement of large, evolved their strong, broad paddles. dolphin-like marine predators. When Stenopterygius was distinguished by its examined microscopically, coprolites can paddles, which contained more joints and reveal not only the fibers of the digested fewer digits than those of other species. matter, but also the fossilized remains of bacterial parasites that inhabited the This magnificent specimen is preserved with digestive tracts of the hosts millions of years an epidermal silhouette. Humboldt ago. From the Jurassic of Chihuahua, Museum. Mexico. Private collection.

77. Class Reptilia, 79. Order , Subclass Ichthyopterygia Suborder Ichthyosaurus megacephalus ajax Jurassic Germany Late Jurassic, Utah

Typifying these classic marine reptiles, Ichthyosaurus was distinguished by the presence of extra digits with fewer joints in its paddle. From other fossils, these air- breathing, dolphin-like creatures are known The regal, long-necked sauropods were by to have fed on pterosaurs and fish, and far the largest land animals that ever lived. rather than laying eggs, and gave birth to With a long, sloping skull and a single live young. This rare and extremely young nostril situated on top of its skull, Ichthyosaurus appears to have died at birth, Apatosaurus (“Mystery Lizard”) was a although the displacement of its member of the diplodocid family, shorter in could easily have occurred after its death. length but much heavier than the closely Private collection. related . Measuring 70 ft. in length and weighing 33 tons, these gigantic 78. Coprolites herbivores possessed long, serpentine necks Ichythyosaur and even longer whiplike tails. Jurassic, Mexico Because the first skeletons discovered were not found associated with any skulls, this dinosaur was originally described as “” (“Thunder Lizard”), a name which persisted until the was finally correctly identified as Apatosaurus, previously known only from a skull that had been named before the discovery of the headless Brontosaurus skeletons, hence its name prevails. For a long time some museums continued to traditionally exhibit their Apatosaurus skeletons with the heads of . Known only from North American specimens, they lived in vast herds that ranged throughout Utah, Wyoming, Colorado, and Oklahoma. This classic leg bone was recovered from the famous Morrison Formation. Brigham Young University.

80. Order Saurischia, Suborder Sauropodomorpha Camarasaurus lentus This 40 foot long sauropod, characterized by Late Jurassic, Utah its short, blunt head and small teeth, laid the largest eggs known, about 12 inches in length. The folded embryo within would have hatched to a size twice the length of the egg. Larger eggs probably would have required a shell too thick for hatching. Hypselosaurus (“High Crested Lizard”) is the only sauropod dinosaur that has ever been found in association with its eggs. Private collection.

82. Order Ornithischia, Suborder Stegosauria Stegosaurus stenops Late Jurassic, Utah

This juvenile skull specimen, its body measuring 17 feet in length, is considered one of the most perfectly preserved sauropods ever to be recovered. Sauropod footprints indicate that these gentle herbivores cared for their young, guarding them on all sides as they wandered together, feeding on the highest tree branches. Found in the famous Cleveland Lloyd Quarry. Carnegie Museum. Discovered in Colorado in 1877, Stegosaurus (“Plate Lizard”) grew to a 81. Order Saurischia, length of up to 30 feet and weighed up to 2 Suborder Sauropodmorpha tons. The bony armored plates guarding the Hypselosaurus priscum neck, back and tail of the huge Jurassic Cretaceous, France herbivore were attached to powerful skin muscles, and were probably capable of being raised and lowered to protect the spine Apatosaurus (Brontosaurus) and or the flanks. Honeycombed with Stegosaurus, its flexible skull capable of capillaries, they may also have served as a expanding to accommodate oversized heat exchange for warming (or perhaps chunks of food. cooling) the animal’s bloodstream, although their actual placement and function remain an enigma.

Aiding in the precision of the movement of the enormous hind-quarters and spiked tail, an enlargement of the spinal cord at the pelvis, much larger than the creature’s brain, While some believe that they were too huge was long believed to be its “second brain.” and clumsy to hunt, scavenging on carrion For its bulk, Stegosaurus had the smallest instead, others believe them to have been skull of any dinosaur, with a brain no larger agile runners and swimmers, capable of than a walnut. Its front legs, only half the hunting in packs for large prey. Trackways length of its back legs, indicate that it found in Texas indicate that such predators probably evolved from a 2-legged ancestor indeed chased herds of much larger and could easily have reared on its strong dinosaurs, and Apatosaurus vertebrae, hind limbs to feed on the higher tree scarred by the teeth of an Allosaurus, have branches. The deadly spikes attached to the been unearthed. tip of its powerful tail were used as a defense against predators in Late Jurassic Sporting strong, 3-fingered claws at the ends Colorado, Oklahoma, Utah, and Wyoming. of its short arms, this creature grew to 36 Found in the Cleveland Lloyd Quarry. U.S. feet or more in length and weighed 1 to 2 National Museum. tons, possibly reaching full maturity in as little as 5 years. Although they have been 83. Order Saurischia, found in Africa, Australia, and perhaps even Suborder Theropoda Asia, Allosaurus are most common in North Allosaurus fragilis America, some 40 individuals coming from Late Jurassic, Utah a single quarry (possibly having perished together). Found in the Cleveland Lloyd Its massive, yet open, lightweight skull a Quarry. marvel of engineering, the fearsome Allosaurus (“Different Lizard”) was the 84. Order Ornithischia, predominant carnivore in North America Family Camptosauridae during the Late Jurassic, and probably fed Camptosaurus browni on such herbivorous dinosaurs as Late Jurassic, Utah mountain ranges and new islands were being formed.

The drifting of the continents toward the polar regions brought on significant changes in the seasonal weather. No longer able to roam between the continents, many of the later dinosaurs evolved exclusively in Asiamerica. The dominant creatures of the period, most species lasted no more than 5 million years before disappearing from the fossil record, often followed by more advanced descendants. This period lasted until 65 million years ago, ending with a catastrophic mass-extinction second only to that of the Permian. Nearly half of all the A primitive ornithopod (“Bird Foot”), Cretaceous plants and animals, both marine ranging in length from 12 to 23 feet and and terrestrial, suddenly vanished. Among weighing up to 1000 pounds, Camptosaurus them were the dinosaurs. (“Bent Lizard”) was much larger and less . agile than its hypsilophodontid ancestors. 85. Infraclass Teleostei Short but sturdy, its 5-fingered forelimbs Order Leptolepiformes were adapted to bearing weight, although Cearana fossilized footprints indicate that it was also Early Cretaceous, Brazil thoroughly capable of walking bipedally on its 4-toed hind legs. Found in the Cleveland Lloyd Quarry.

THE CRETACEOUS PERIOD from 140 million to 65 million years ago

Marking the appearance of flowers, the fertile Cretaceous period was named for vast deposits of chalk (creta in Latin), rich in fossils and widely distributed throughout the The appearance in the fossil record of the world. The distribution of the continents heterogeneous group of leptolepids marks was beginning to resemble that of the the arrival of the modern teleost, or bony, present, although a great shallow sea fishes, which now dominate the world’s flowing from Canada to the Gulf of Mexico aquatic environments. Armed with a separated the supercontinent of Laurasia into mouthful of small, sharp teeth, these Asiamerica (East Asia and Western North elongate, tapering fish became widespread America) and Euramerica (Europe and throughout the Late Jurassic and Early Eastern North America). Marked by a rich Cretaceous. Spectacularly preserved in mud emergence of advanced dinosaurs, the Late concretions, Cearana is a well-documented Cretaceous, 75 million years ago, was a time variety known to have preyed on its own of tremendous volcanic upheaval as species, some individuals having died in the process by choking on prey too large to there is little doubt that they were warm- swallow. Unlike more primitive fish with blooded. Its brain had unusually large primarily cartilaginous skeletons, such as cerebral hemispheres for a dinosaur, sharks and lobe-fins, the early teleosts suggesting complex behavior more birdlike possessed fully ossified internal skeletons. than reptilian. Of the few fossilized battles From the famous Santana Formation of between dinosaurs that have ever been Brazil. Private collection. found, two involved Dromaeosaurs, providing spectacular evidence of their 86. Infraorder Denonychosauria, behavior. One find in Montana indicates Family that they hunted in packs, while a one-on- Dromaeosaurus albertensis one battle to the death with a Protoceratops , Canada was discovered in the Gobi Desert. Their combination of intelligence, swiftness, and the sickle claw places these creatures among the most dangerous of the dinosaurs. Royal Tyrrell Museum of Paleontology.

87. Order Ornithischia, Family Hadrosauridae Anatosaurus annectens Late Cretaceous, Montana

Popularly known as a “Raptor”, this ferocious creature was armed with one lethal, sickle-shaped claw on each foot, held in a retracted position when it walked and extended for slashing the bellies of its victims with multiple kicks of its powerful hind legs. Discovered in 1914 by Barnum Brown, this rare and highly specialized group of theropods was not fully understood until the discovery by John Ostrom in 1964 of Deinonychus, an early dromaeosaur This fibular fragment with a splendidly succeeded in the Late Cretaceous by preserved skin impression is from a partially Dromaeosaurus (the first such dinosaur to mummified duckbilled dinosaur found in the be discovered), and the Mongolian Hell Creek Formation. Private collection. Velociraptor. 88. Order Ornithischia Because Dromaeosaurs (“Running Family Hadrosauridae Reptiles”) display a striking affinity to birds, Corythosaurus casuarius particularly the Jurassic Archaeopteryx, Late Cretaceous, Alberta

88. Order Ornithischia, The crested Corythosaurus (“Helmet Family Hadrosauridae Lizard”), with its short muzzle and tall, Maiasaura peeblesorum hollow crest, lived in herds throughout the Late Cretaceous, Montana forests of western Canada where it browsed on tree leaves and pine cones. Equipped These gentle duckbilled dinosaurs left in the with strong, bulging cheeks, it was capable fossil record a very detailed picture of their of chewing a mouthful of food while storing way of life. Herds of Maiasaura (“Mother another. Growing to lengths of 33 feet and Lizard”) appear to have nested together in weighing over 4 tons, these peaceful vast colonies along the shores of Cretaceous herbivores ranged north of the Arctic Circle rivers of Montana. Juveniles and hatchlings in search of food and migrated south during of varying ages have been found in these the long winters, which were less cold in nests, exhibiting evidence of prolonged Late Cretaceous times than they are now. parental care. The eggs were carefully Known for protecting and feeding their arranged in regular patterns in large, dug-out young, these duckbills may have relied upon mounds, each an adult body length from the their prominent head crests for recognition next. Adults, which grew to lengths of 30 during their mating season. feet, appear to have returned to these nesting

sites year after year. Although they possessed no significant defense against predators, their keen sense Browsing on their hind legs among the tree of vision, hearing, and smell served to warn branches or cropping the undergrowth on all them of approaching danger. Females and fours, these peaceful herbivores were immature individuals had smaller crests. defenseless against the ferocious weapons of Like other crested duckbills, when their predators. Migratory hadrosaurs such Corythosaurus called to each other the as Maiasaura appear to have fed and sound resonated through the long air protected their young until they were old passages of their nostrils (which extended enough to join the herd. Discovered in 1976 into their hollow crests) producing a far- by John R. Horner. Museum of the Rockies. reaching, bugle-like honk. Linked with blood vessels, such extended nasal passages 89. Coprolites also may have evolved for the purpose of Hadrosaur warming the arctic air before its arrival into Cretaceous, Canada the lungs. From the Royal Ontario Museum.

91. Order Ornithischia, Suborder Ceratopsia Protoceratops andrewsi Late Cretaceous, Mongolia

Regarded as the earliest known horned dinosaur (although it only possessed small crests where the great horns of its giant These coprolites were discovered in descendants would be), this exquisite skull association with the fossilized remains of of an adult individual is from the Polish- duck-billed dinosaur nests in Saskatchewan. Mongolian expedition. Private collection. 92. Order Ornithischia, 90. Order Saurischia, Suborder Ceratopsia Suborder Theropoda Chasmosaurus belli Oviraptor philoceratops Late Cretaceous, Alberta Late Cretaceous, Mongolia Of the long-frilled Ceratopsian dinosaurs of the Late Cretaceous, Chasmosaurus (“Ravine Reptile”) is the earliest known. Extending from the back of the creature’s head, a sturdy, spiked frill protected its neck and part of its back.

In Mongolia in 1922, an Expedition from the American Museum of Natural History led by Roy Chapman Andrews set out to find remnants of early humankind. Instead they discovered several nests of Oviraptor (“Egg Thief”) eggs, the first dinosaur eggs ever located, in what must have been a large nesting ground. Because skeletons of the small, frilled dinosaur Protoceratops were found in association with the nests, the eggs were long attributed to them. More recent expeditions have uncovered a fossil female Oviraptor (a small, beaked, and toothless theropod) actually sitting on a clutch of Large openings in the frill reduced the unhatched eggs, revealing that weight of the bone mass. It had 2 small Protoceratops was the intruder. From the horns over the brows and one on its parrot- historic Roy Chapman Andrews Gobi beaked snout. Living in large, migrating Expedition. Alf Museum. herds and measuring over 16 feet in length, these herbivorous grazers have been found Distinguished by thickly domed skulls in Alberta, New Mexico, and Texas. rimmed with bony spikes, rival males are Though not as well-equipped as its believed to have established dominance over descendant, Triceratops (“Three horned their herds through fierce contests of head- Face”), Chasmosaurus was capable of butting. This supposition is further warding off attacks by fierce tyrannosaurs. evidenced by their neck and backbones, Females of the genus are distinguished by which were specially reinforced with strong their diminutive horns. This impressive ligaments for absorbing and distributing creature was one of the first dinosaurs to be severe shocks to the head. Ancestral to the found along with an impression of its skin, larger and more advanced the patterns of its large mosaic scales Pachycephalosaurus of North America, suggesting contrasting color patterns. Stegoceras may have evolved from an ancestor of such horned dinosaurs as 93. Order Ornithischia, Triceratops and migrated from Mongolia Family Pachycephalosauridae before the continents divided. Royal Stegoceras validus Ontario Museum. Late Cretaceous, Alberta 94. Suborder Theropoda, Family Tyrannosauridae Albertosaurus sarcophagus Late Cretaceous, Alberta

Sometimes known as Gorgosaurus, Albertosaurus (“Alberta Lizard”) was a smaller, slender tyrannosaur (“Tyrant Lizard”) that only grew to a length of about 26 feet and a weight of 2 tons. Despite its size in comparison to its larger relatives, it

was a ferocious predator that probably Among the rarest of dinosaur remains, the hunted the herbivorous horned and armored enigmatic boneheads are known mostly dinosaurs of the Late Cretaceous lowland from fragments of skulls and skeletons, forests of Alberta. Presumably descended making their relationships to other from a small, Late Triassic theropod and ornithischians groups difficult to prove. named for the province in Canada where it Growing to lengths of over 6 feet and was discovered, Albertosaurus was also weighing up to 120 pounds, Stegoceras common in Montana just before the end of (“Horny Roof”) had keen vision and an the Mesozoic Era. acute sense of smell. Various names have been given to the Possessing sharp teeth, this slow–moving, dozens of Albertosaurus skeletons bipedal creature is believed to have fed on discovered during the past century, but only insects, fruits, and leaves. Roaming in herds recently has their relation to each other been that ranged throughout the hills of eastern recognized. Like all tyrannosaurs, Asia and western North America, the Albertosaurus only has 2 fingers on each boneheads apparently had lifestyles similar claw, the vestigial third finger a useless to those of modern sheep and goats. remnant of its 3-fingered Jurassic ancestors. the last of the flying reptiles. Texas Royal Tyrrell Museum of Paleontology. Memorial Museum.

95. Superorder Archosauria, 96-98. Suborder Theropoda, Suborder Pterosauria Family Tyrannosauridae Quetzalcoatlus northropi Tyrannosaurus rex Late Cretaceous, Texas Late Cretaceous, Montana

One of the largest known predators to have walked the Earth (the females distinctly larger than the males), this invincibly massive, ferocious carnosaur of Late Cretaceous western North America and Asia was discovered in 1902 by the adventurous collector Barnum Brown. Surpassed in size only by the South American carnosaur Giganotosaurus, Tyrannosaurus rex (“Tyrant Lizard King”) grew to lengths of as much as 50 feet, towering 20 feet high and Named for the ancient Mexican feathered weighing 5 to 7 tons. Their heads alone serpent-god Quetzalcoatl, the giant measured 4 to 5 feet, sporting jaws lined Quetzalcoatlus was estimated at twice the with long, saw-edged teeth, each one size of the largest known pterosaurs known supported by ranks of replacements. at the time, the Pteranodons of the Kansas Reaching maturity within 5 years, the life Chalk. Only one wing was found, indicating spans of these enormous creatures may have a wingspan of 36 to 39 feet with a weight of surpassed 100 years. 190 to 220 pounds, making it the largest known flying creature. With a low, narrow crest and a long, sharp, toothless beak, this giant is better known from smaller, more revealing specimens found in the same region, which were either younger individuals or a smaller species. Although they were dynamically suited for fishing over the sea, their remains are not found in marine deposits or even near any sizeable freshwater lakes, but are instead found in the silts of the vast floodplain of an ancient inland system of stream channels over 250 miles from the nearest sea, suggesting the possibility of their having been scavengers of carrion instead. Similar discoveries in Fossil evidence of their actual metabolism is Canada and Israel indicate the possibility of magnificently preserved in the sequential a wide distribution. Their colossal humerus, rings of growth-spurts which scar the teeth. discovered in 1971 by Douglas A. Lawson While strictly regarded by some as nothing and Wann Langston, Jr., belonged to one of more than scavengers, owing to their greatly reduced forelimbs which could not even reach their mouths, others consider these creatures the most fearsome hunters ever to have existed, balanced for swift running by their long tails.

Since 1978, the extinction of the dinosaurs has largely been attributed to cosmic intervention in the form of an enormous meteorite impact on the Earth 65 million years ago. Discovered by scientists Walter Presumed to have dealt mostly with the and Luis Alvarez, Frank Asaro, and Helen animal’s senses, the brain of Tyrannosaurus Michel, a thin layer of the exceedingly rare rex was not small for a dinosaur although element iridium (commonly found in compared to the size of the creature’s body meteorites) forms a boundary worldwide it was remarkably diminutive. This cranial between Cretaceous deposits and those of endocast preserves the size and shape of the the Tertiary period, apparently the global brain of a Tyrannosaurus rex. fallout from a devastating collision with a large extraterrestrial body. Heat trapped on the planet’s surface by the dense atmospheric debris may have raised global temperatures, killing off the majority of land and sea organisms in a single catastrophic event. The gigantic Xixulub crater in Yucatan, Mexico was blasted by such an impact around the time of the Cretaceous extinction.

Most meteorites come from the vicinity of This isolated maxilla, once the largest the asteroid belt, the orbiting fragments of known, is from the University of California, metal and rock which are the remnants of a Berkeley. This spectacular skull, from one failed planet and of the actual creation of our of the largest ever found, is from the solar system some 4.6 billion years ago. Museum of the Rockies. About 22,000 years ago this meteorite, composed of 95% pure iron, left a crater 99. Meteorite over 3,600 feet wide and 525 feet deep. A Meteor Crater, Arizona fragment of the original meteorite, this pristine relic of the formation of the solar system was found in the famous depression of Meteor Crater, Arizona. Private collection. THE CENOZOIC ERA 100. Phylum Tracheophyta from 65 million years ago to the present Class Gymnospermida Gingko adiantoides A series of glaciations distinguishes the era Paleocene, South Dakota that includes the present. By the time the dust settled on top of the last Cretaceous sediment, another era had dawned, the Cenozoic ("Recent Life"), giving rise to rapidly diversifying groups of mammals. No longer relying on their diminutive size for survival in a world dominated by giants, the mammals immediately assumed the roles of chief competitors for supremacy over the newly abundant territory left by the passing of the dinosaurs, producing such giants of their own as the great wooly mammoths of the Ice Age.

As the early mammals diversified throughout the Paleocene ("Ancient Recent") and the subsequent ("Recent Dawn") epochs, from 64 to 36 million years ago, many of the modern The earliest gingkoes, or maidenhair trees, mammal groups began to appear in the fossil appeared in the Permian. Their record. Of these early mammals, several characteristic fan-shaped leaves did not became extinct as rainforests retreated from grow on the tree in totally uniform shapes, the frost during the Oligocene ("Few exhibiting combinations of the differing Recent"), which ended 26 million years ago. ancestral forms from which they were The ("Less Recent"), which derived. The unmatching leaves in this followed, lasted until 6 million years ago. specimen probably came from the same tree. Along with the appearance of large, new Sexually distinct, these ancient trees mountain ranges, the spreading of grasslands reproduce through pollenation by males of during this period gave rise to a vast the pitted ovules grown by females. A radiation of grazing animals. nourishing group throughout the Mesozoic, gingkoes reached their peak during the As the climate became colder throughout the Jurassic and were long thought to be extinct Pliocene ("More Recent"), from 6 to 1.6 until a single surviving species was million years ago, numerous mammals discovered in China, preserved in some became extinct while modern plants and temple gardens. Found in the same rocks as animals appeared, including early fossil palms, this Gingko is evidence of the humankind. During the Pleistocene ("Most subtropical climates in North America at the Recent") epoch, from 1.6 million to 10,000 dawn of the Cenozoic. Private collection. years ago, vast continental glaciers spread and receded as over half of the giant 101. Class Mammalia, mammals became extinct following the Order Insectivora appearance of modern humans. Icaronycteris index Early Eocene, Wyoming

102. Class Aves, Family Scolopacidae Rhynchaeytes messelensis Eocene, Germany

The disappearance of toothed birds at the Derived from the Late Cretaceous tree- end of the Mesozoic was followed by the dwelling insectivores and surviving virtually appearance of nearly half of the modern bird unchanged except for the adaptation of the groups which, in early Cenozoic times, were forelegs for flight, first appeared in the less diverse and specialized. Insulated by Early Eocene. Employing echolocation as a feathers derived from the scales of their navigational aid, the earliest of these flying theropod ancestors, these warm-blooded insectivores had highly evolved wings that creatures are the only surviving descendants were reinforced by the finger bones. In of the dinosaurs. search of insects over the ancient lakes of Wyoming, some invariably drowned and Wading along the beaches of central Europe became fossilized in the fine-grained lake- at low tide and digging for prey in the sand, bottom sediments. the long-limbed snipe Rhynchaeytes was specially adapted to life as a shorebird. This The last of only 4 animal groups to develop beautifully preserved fossil snipe is from the the power of flight, the early bats gave rise fossiliferous oil-shales of Messel. Private to fruit-eating varieties equipped with collection. powerful vision and unreliant upon echolocation. Exemplified by this perfectly 103. Subclass preserved type specimen, Icaronycteris is Family Clupeidae one of the oldest known bats. From the Knightia humilis famous . Yale Eocene, Wyoming Peabody Museum. ancestor, , Propalaeotherium's 4- toed front and 3-toed hind feet (each with a small hoof), as well as its low-crowned teeth, suggest a life of browsing on the lush undergrowth of the Eocene rainforests of 45 million years ago.

With an arched back and elevated Descended from the primitive Agnatha of hindquarters, this diminutive ancestor of the the Paleozoic and distinguished by their horse probably lived in small herds, running bony internal skeletons and symmetrical in leaps like a deer, with most of its weight tails, these are among the most advanced of resting on the padded soles of its feet rather fossil fish. First appearing in the Early than on the hoofs. The diversification of the Cretaceous, this group of teleost fish, which horse family took place largely during the includes anchovies and sardines, is typified subsequent Oligocene and Miocene epochs by the herring. From the Green River as some took to the rapidly spreading Formation. Private collection. prairies while others remained in the forests. From a rare juvenile specimen unearthed in 104. Class Mammalia the famous fossil deposits of Messel. Order Perissodactyla Humboldt Museum Propalaetherium messensis Middle Eocene, Germany 105. Class Mammalia Order Artiodactyla Merycoidodon culbertsoni Late Eocene, South Dakota

Among the earliest known descendants of Eohippus ("Dawn Horse"), this tiny ancestral horse only reached the size of a These gentle little sheeplike creatures, with fox. Close to the ancestry of rhinoceroses their short limbs and 4-toed feet, roamed the and as well, it also gave rise to the forests and plains of North America in great extinct giant palaeotheres ("Ancient Beasts") herds 25 to 30 million years ago. Except for of Western Europe and Asia when the their prominent canines, the teeth of continents separated from North America Merycoidodon ("Cud Chewing Tooth") were during the Eocene. Like its immediate similar to those of present day deer, indicating that they probably spent most of ("Adjustable One") was somewhat more their time browsing on low shrubs. The advanced than other early . Its thousands of fossils found in the White forward-facing eyes, evolved for focusing River badlands of South Dakota make this on single objects, enabled it to leap from primitive cloven-hoofed animal, related to branch to branch with an accuracy of depth camels and swine, one of the most abundant perception superior to that of earlier and well-known of the early North mammals. Flourishing throughout forests of American mammals. First appearing in the Europe and North America some 40 to 50 Late Eocene about 38 million years ago, million years ago, these long-tailed, cat- their herds were quite common throughout sized creatures were agile quadrupedal the Oligocene. They belonged to a climbers that presumably fed on fruits and successful group of even-toed ungulates insects. Restricted to arboreal life (living in called Oreodonts, believed to have been trees) by competition with the growing ruminants, or cud chewers. This exposed in- number of ground-dwelling rodents, this situ skeleton is from the South Dakota primitive ancestor of lemurs and , Badlands. Private collection. with its 5-digited, grasping hands and feet, is believed to have indirectly given rise to the 106. Class Mammalia, higher primates. Private collection. Order Primates Adapis parisiensis 107. Order Primates, Middle to Late Eocene, France Family viejaensis Early Oligocene, Texas

Apparently derived from the lemur-like adapids, early prosimians known as omomyids appeared in North America and Europe at the dawn of the Eocene. Diverse throughout the period, particularly in North Among the oldest groups of placental America, only a few genera survived into mammals, the first primates evolved from the Oligocene. Resembling tarsiers, earlier primeval insectivores (possibly tree ) species appear to have been insectivorous, about 70 million years ago. Equipped with whereas the relatively late Rooneyia was and vertical front teeth, Adapis probably a frugivore. The position of the eye socket suggests a distant link between these 109. Order Primates, basal primates and living anthropoids. The Subfamily Proconsulidae lone representative of its species, the large- africanus eyed Rooneyia was a contemporary relative Miocene, Africa of the first prosimians to appear in Africa. University of Texas.

108. Order Primates, Family Pliopithecidae Aegyptopithecus zeuxis Middle Oligocene, Egypt

Along with the shrinking of the prehistoric Tethys Sea, the extinct early probably spread from Africa to Europe and Asia when the continents were once again linked. As the climate shifted and grasslands replaced the forests, some primates spread to the savannas, learning to stand upright and evolving cooperative societies for protection from the dangers that lurked in the tall grass. Sometime during the Miocene epoch (from In Egypt's Sahara, the exposed remains of a 24 to 6 million years ago) the ancestral line lush 33 million-year-old tropical rainforest of the hominids (the family that includes the have yielded rare fossils of Aegyptopithecus great apes and humankind) diverged from (" From Egypt"), perhaps the oldest that of the apes. With limbs adapted for known direct ancestor of the great apes and crawling through trees, the quadrupedal humankind. Commonly known as the Proconsul (named for a once "Dawn Ape", this tiny tree dwelling primate, popular in the London Zoo) is largely no longer than a cat, probably fed on insects, regarded as being ancestral to apes and fruit, and nuts. Possessing a short tail and hominids, possessing characteristics of both. primitive snout, its forward-facing eyes and Larger than monkeys, this tailless 32 teeth link it with such later Miocene apes dryopithecene ("Oak Ape") inhabited the as Proconsul. From the famous Fayum fringes of the forests and savannas of Depression. Cairo Geological Museum. Miocene Africa from 22 to 15 million years ago, possibly living and hunting in 111. Insects in Amber primitively cooperative groups like the Early Miocene, modern chimpanzee, although no evidence Kenya, Columbia, Dominican Republic of this behavior has ever been found. Discovered in 1948 by Mary Leakey. National Museum of Kenya.

110. Class , Family Isuridae Carcharodon megalodon Miocene, South Carolina

Trapped in resin that oozed from the trunks of the ancient conifer trees before hardening into amber, fossil insects are found throughout the world, preserved to their tiniest bristles, including their last exhaustions and excretions. Related to the petroleums, amber is usually clear and yellow in color. Lumps containing insect inclusions provide an important record of the prehistoric faunas of the locales and Descended from primitive Devonian sharks, geological periods in which they are found. true sharks appeared during the Jurassic. Formerly thought to contain only Characterized by their streamlined bodies, impressions of the decomposed remains of powerful tails, and pointed snouts, these insects, amber in fact contains the actual fearsome marine creatures have to swim preserved remains of its hapless victims. In constantly due to their lack of buoyancy, 1992 revolutionary researchers at the although recent studies have revealed their University of California, Berkeley and the sleeping habits on the ocean bottoms where American Museum of Natural History in they have been observed resting absolutely New York successfully recovered and still for hours at a time. Following the cloned DNA from 30-million-year-old extinction of the marine reptiles, sharks insects preserved in amber. Suspended in became (and remain) the dominant predators amber for over 20 million years, these of the seas. Ancestral to the modern great termites and tiny flies are from the Miocene white sharks, the extinct Miocene of Columbia and the Dominican Republic. Carcharodon megalodon ("Great Sharp The spider, perfectly preserved in a bead of Tooth") of 20 million years ago may have colorless amber, is from Mombassa. Private reached lengths of 45 to 50 feet. Equipped collection. with hundreds of sharply serrated and replaceable teeth, its gristly jaws were 112. Order Primates, capable of the unique thrusting action of its Superfamily Hominoidea modern survivors, which helps prevent its Kenyapithecus wickeri prey from making last-moment escapes. Early to Middle Miocene, Kenya Private collection. australopithecine strain that led to humankind. National Museum of Kenya.

113. Order Primates, Family Pongidae Sivapithecus indicus Late Miocene, Pakistan

Discovered by in 1961, these jaw fragments are the only known remains of what appears to be an early hominoid species that inhabited the early to Middle Miocene forests of Kenya from about 14.4 to 12.5 million years ago. Upon close examination it was determined that there was little, if any, difference between this jaw and that of “Ramapithecus” except that it is a few million years older and was found on a different continent, separated from any known “Ramapithecus” find by a distance of thousands of miles. Formerly known as “Ramapithecus”, Sivapithecus (“Shiva’s Ape”) was long Exhibiting such humanlike features as regarded as the Miocene ancestor of the reduced canines and front teeth along with a Pliocene hominids that gave rise to correspondingly shortened snout, humankind. Owing to the erroneous Kenyapithecus (“Kenya Ape”) is largely reconstruction of its fragmentary dental regarded as the most likely antecedent of the arcade in a humanlike parabolic arc, it was australopithecines. These extremely popularized as the earliest and most specialized teeth imply a small bipedal primitive hominid. Since the subsequent hominoid with advanced manipulative skills. consolidation of “Ramapithecus” with the Erect walking, freeing the hands for the earlier known Sivapithecus, the discovery of preparation of food, reduces the demands on more complete facial skeletons in Turkey the teeth which, in turn, would lead to a and Pakistan ultimately revealed this genus reduction in their size. Perhaps a limited as the ancestor of the Southeast Asian population was restricted to a small area, orangutans. which would account for its scarcity, although “Ramapithecus” finds are DNA sequencing suggests a hominid widespread throughout Europe and Asia. divergence in Africa from a common While the later Asian group is believed to ancestor with the chimpanzee between 6 and have given rise to the orangutan, this earlier 5 million years ago. Despite this evidence, African genus may well have produced the the fragmentary fossil record of Sivapithecus appeared to suggest a contradictory date for near Lake Turkana). Differences in wear the hominid split of between 15 and 9 between the first and second molars suggest million years ago in Asia. Since the DNA that their eruptions were separated by sequence of orangutans suggests a several years. divergence of hominids, , and gorillas from a common ancestor with Discovered at the Lothagam site in 1967 and orangutans between 11 and 12 million years dated at 5.5 million years, the older ago, the fossil record is confirmed by is the earliest known evidence of molecular biology due to the discovery in the hominid line. The wealth of afarensis Africa of Kenyapithecus, an earlier Miocene from Laetoli and Radar have ancestor of both the Asian ramapithecines provided enough diagnostic information to and the later African hominids. Geological identify the Lothagam remains with the Survey of Pakistan. latter species. The exposed and well- preserved root system exhibits 114. Order Primates, characteristics exclusive to afarensis. The Family socket of the missing suggest Australopithecus sp. that this most archaic of hominids may have Early Pliocene, Kenya possessed somewhat more prominent canine teeth, its age placing it more or less contemporaneous with the divergence of hominids and chimpanzees from their common ancestor. Kenya National Museum.

115-116. Order Primates, Family Hominidae Australopithecus afarensis Middle Pliocene, Ethiopia

Among the oldest recognized hominid remains are two mandible fragments found in the North Kenya Rift Valley at the Lothagam and Tabarin sites. Falling within the recorded range of dimensions and contours of Australopithecus afarensis, they are generally attributed to that species. The younger fragment, discovered at the Tabarin site in 1984, is dated 4.15 million years, and thus was a contemporary of the primitive The genealogy of humankind emerges with Australopithecus anamensis (found in 1996 the line of australopithecine hominids, which appears to have begun between 4 and 5 million years ago with the appearance of smaller heads and brains. Possessing Australopithecus anamensis (“Southern Ape smaller canines than their quadrupedal of the Lake”) and its earliest descendants, ancestors, they presumably foraged in the well-documented Australopithecus family groups for fruits and seeds along the afarensis (“Southern Ape of Afar”). vanished lakes and streams of Ethiopia and Presumably descended from a divergent Tanzania, possibly sleeping in high tree group of Miocene apes such as branches to avoid predators. Disappearing Kenyapithecus, these early species of gracile by 2.5 million years ago, this hominid australopiths are the most primitive known. species gave rise to all of the subsequently Among the oldest and most complete varied tribes of Australopithecus and Homo. remains of an erect-walking ancestral Courtesy of the Institute of Origins. hominid ever found, this amazing afarensis National Museum of Ethiopia. skeleton is dated at about 3.2 million years. Known throughout the world as “Lucy” 117-118. Order Primates, (from a Beatles song), it was discovered in Family Hominidae Radar, Ethiopia in 1974 by Donald Johanson Australopithecus afarensis and Tom Gray. Lucy was 3-and-a-half feet Middle Pliocene, Ethiopia tall and about 25 years old when she died. Though her scarcely worn wisdom teeth had only recently erupted, she was already showing signs of bone disease on her spine. Whether she accidentally drowned or quietly laid down in the sand and died, her remains were deposited in the shore of an ancient lake and covered over by sediment until eventually exposed by rain.

In 1975 the bones of at least 13 individual hominids were discovered strewn down a slope at Radar, Ethiopia, now known as the famous 333 site. Apparently exposed and washed down from the top of the slope by recent rains, the inference was that they had originally been deposited together. Unmarked by signs of aggression or

scavenging, the group seemingly perished Lucy herself had an apelike face with a low together about 3.5 million years ago, forehead, resembling far more her recent possibly in a flash flood. Popularly known arboreal, chimp-like ancestors than her as the “First Family,” this extraordinary find distant Homo descendants. With slimmer is evidence that even the earliest hominids hips and narrower birth canals, females lived in bands (or tribes). apparently gave birth to infants with far Tanzania, and South Africa. Descended from afarensis and thoroughly established by 3 million years ago, the gracile africanus species is believed by many to be intermediate between afarensis and Homo habilis, although its direct relation to humankind is still the subject of debate due to the robust size of its molars, a characteristic of subsequent species of australopiths not shared by the genus Homo.

A controversy arose over the naming of the species because the closer in time the separate species of hominids are to their original common ancestor, the more they look alike, making it difficult to distinguish between them. Close to the ancestor of the gorilla and even closer to that of the chimpanzee, afarensis was among the earliest of the divergent line that led to Homo; in fact the origin of the human race can be traced directly back to this ancient Using their hands for gathering and tribe of gracile australopiths. Ranging from carrying, Australopithecus africanus walked 3 to 5 feet in height and weighing from 60 to erect, presumably foraging for roots and 90 pounds, afarensis had long arms with seeds and perhaps even scavenging remains slightly curved finger and toe bones, from carnivore kills in small groups suggesting at least a partially arboreal life. throughout the tropical savannas of eastern These composites of a male skull and hand and southern Africa. Formerly recognized are reconstructed from the incomplete as “Plesianthropus (“Near Human”), this remains of several individuals from the 333 skull was discovered by Robert Broom in site. Collected by Donald Johanson in 1947 in the Sterkfontein quarry and became Radar, Ethiopia. Courtesy of the Institute of popularly known as “Mrs. Ples”, although it Human Origins. National Museum of is now recognized as Australopithecus. Ethiopia. From 3 to 4 feet tall and weighing 45 to 90 pounds, these small apelike creatures ranged 119. Order Primates, throughout the grasslands of Kenya, Family Hominidae Ethiopia, Tanzania, and South Africa, living Australopithecus africanus alongside their evolutionary descendants for Late Pliocene, South Africa over a million years. They became extinct about 1 million years ago, survived, From 3 million to 1 million years ago, according to some paleoanthropologists, by several species of bi-pedal ape-men their Homo descendants. Transvaal coexisted throughout Kenya, Ethiopia, Museum. 120. Order Primates, 121. Order Primates, Family Hominidae Family Hominidae Australopithecus africanus transvaalensis Australopithecus aethiopicus Late Pliocene, South Africa Late Pliocene, Kenya

Darkly stained by manganese, the enigmatic “Black Skull” was discovered in 1985 by Discovered by Raymond Dart in 1924 in a Alan Walker on the west shore of Lake limestone cave in Taung, South Africa, this Turkana in northern Kenya. Dated at 2.6 extraordinary specimen of a 3-year-old million years, this vegetarian hominid gracile australopith is the first ancestral exhibits primitive skull traits of the earlier hominid fossil ever to be found. Once afarensis species from which it was derived, known as “The Missing Link”, it is now along with advanced facial characteristics of formally recognized as Australopithecus both the later robustus and boisei species. africanus, popularly known as the Taung Child. The opening for the spinal nerves, Prior to the Black Skull’s discovery, the located at the bottom of the skull rather than direct ancestor of the robust hominids was near the back, indicates this young hominid firmly believed to be Australopithecus stood erect and walked on 2 feet, a fact africanus. The age of aethiopicus, however, reinforced by the subsequent discovery of with its massive teeth and sagittal crest, humanlike africanus pelvic bones. implies that it, and not the gracile africanus, is the intermediate stage between afarensis Judging by other fossilized bones of known and the robust australopiths, thus giving extinct mammals found in the cave, the credence to the standing of africanus as the geological age of the Taung Child has been transitional species between afarensis and estimated at about 2 million years. Homo, a more plausible scheme according Remarkably preserved with its furrows and to many paleoanthropologists. Possessing convolutions intact, the fossilized cast of the the smallest brain of any known hominid, Taung Child’s brain indicates that these this profoundly controversial fossil ancestral hominids possessed small brains, provoked a complete redrawing of midway in size between those of apes and humankind’s family tree. From Lake humans. Transvaal Museum. Turkana. Kenya National Museum. 122. Order Primates, before giving rise to boisei. Ascribed Family Hominidae female from the Sterkfontein Valley. Australopithecus robustus Transvaal Museum. Late Pliocene, South Africa 123. Order Primates, Family Hominidae Australopithecus boisei Late Pliocene, Tanzania

Although the early gracile australopiths were scarcely larger than a chimpanzee, the later robust species were a little over 5 feet in height. Walking upright throughout the savannas of eastern and southern Africa, these larger hominids were gatherers who fed on leaves, seeds, berries, and perhaps From a specimen discovered by Mary insects, possessing little, if any, knowledge Leakey in the Olduvai Gorge in Tanzania of toolmaking. Presumably descended from and named Zinjanthropus (“East African the gracile afarensis, the robust australopiths Human”) by Louis Leakey, this early were a branch that did not survive. hominid was subsequently renamed to include it in the closely related groups of Largely regarded as a female (due to its australopiths. 1.8 million years old, it was size), this individual was discovered in 1950 the first fossil of an australopith to be at the Swartkrans cave in Transvaal, where successfully dated. Ranging in height from its carcass had apparently been dragged by a 5 to nearly 6 feet, they were about the size leopard. An advanced primate closely of modern humans. related to humankind, Australopithecus robustus was not on the evolutionary path Australopithecus boisei (“Boise’s Southern that led to Homo. Though it has been Ape”) was named for one of the Leakey’s argued by some that robustus and africanus benefactors, Charles Boise. Despite their are simply males and females of the same significantly smaller brains and apelike species, undisputed robustus finds appear to skulls (with a pronounced sagittal crest for be exclusive to South Africa. Appearing anchoring powerful jaw muscles), in many about 2.5 million years ago, robustus died ways “Zinj” resembled humans. Apparently out after about a million years, though not the largest of the 5-million-year-old line of australopiths, “Zinj” was also the last. reproducing by their early teens, with all of Possibly killed off by the more advanced their adult molars by age 3. Homo habilis, whose chipped tools are sometimes found with the remains of these Their elongated, apelike arms were hominids, the species became extinct about extremely adapted for climbing, but with 1 million years ago. Unassociated jaw from their facile hands, long freed by walking the Koobi Fora Formation of East Turkana. upright, they were prolific makers of stone Kenya National Museum. Skull from the tools for breaking open bones and scraping National Museum of Tanzania. meat, as well as the first known to favor one hand over the other. The long-held belief 124. Order Primates, that Homo habilis was the first hominid to Family Hominidae make stone tools may have been dispelled Homo habilis by the discovery of the Ethiopian Late Pliocene, Kenya Australopithecus garhi (“Surprise Southern Ape”) fossils, found in the vicinity of fossil animal bones that had been scraped with stone implements 2.6 million years ago. The famous 1470 skull was collected at Koobi Fora by Bernard Ngeneo and Richard Leakey. Kenya National Museum.

125. Order Primates, Family Hominidae Homo erectus Late Pliocene, Kenya

Contemporary with “Zinj” and descended from a common ancestral australopith, these ancient, more advanced hunter-scavengers are the earliest to be classed in our genus, Homo (Man), due to the abundant evidence of their tools found in the Olduvai Gorge. It is from these primitive tools that Homo habilis (“Handy Man”) derives his name. An early form of habilis, this 2-million- year-old individual is separately classified by some as Homo rudolfensis. Ranging from 4 to 5 feet in height and living perhaps 30 years, they were sexually mature and Although possessing the thickest skull of the kill. Remains of crippled individuals any hominid, the superior intelligence of hint at the compassionate nature of their Homo erectus (“Upright Man”) enabled this society. Showing remarkable self- Early Stone Age hunter to venture from the awareness, their ritual burials with floral ancient habitats of its African ancestors to offerings are the oldest known. Bear skulls thinly populate such diverse regions as found enshrined in their caves suggest the Europe and Southern Asia, perhaps emergence of primitive mystical expression. following the migrating herds of large mammals as they hunted.

Descended from Homo habilis by 1.7 million years ago and credited with the discovery of fire, their improved hunting methods appear to have included the use of brush fires to drive herds of big game into ravines. Homo erectus sites yield abundant evidence of tent dwellings, hearths, and sophisticated stone tools. Possibly growing to heights of 6 feet, their brains were substantially larger than those of their more primitive predecessors. One of the earliest known erectus skulls, separately identified by some as Homo ergaster, dated at 1.7 million years. No. KNM-ER 3733, collected at Koobi Fora by Bernard Ngeneo and Richard Leakey. Kenya National From 70,000 to 40,000 years ago these Museum. hominids inhabited large caves of

Mediterranean Europe, the Middle East, 126. Order Primates, northern Africa, and Russia, some sheltering Family Homindae up to 40 individuals at a time. Probably as a Homo sapiens neanderthalensis result of interbreeding with our own Middle Pleistocene, Israel subspecies, this once flourishing culture

became extinct about 30,000 years ago. First discovered in the Neander Valley, From Mt. Carmel, Israel. Harvard West Germany, this short rugged University. subspecies, with its thick skull and heavy brow ridges, had a larger brain than modern 127. Order Proboscidea, humans and probably spoke a primitive Family Elephantidae language. Despite their big bones and heavy Mammuthus jeffersoni exilis build, Neanderthals grew to a height of 5 Pleistocene, California feet, 7 inches. Appearing about 200,000 years ago, their advanced intelligence and Evolved from Eocene African elephants, the adaptability enabled them to survive in the giant dome-headed, spiral-tusked mammoths harsh arctic climate of the last Ice Age. migrated into North America over the land Clothed in animal skins cut with stone tools, bridge from Asia 1.5 million years ago. they hunted in groups, apparently sharing With their thick coats of shaggy, reddish fur insulating them against the harsh climates of This large, ferocious saber-toothed cat the tundra regions during the Ice Age, they evolved in North America and spread widely used their great tusks to sweep aside snow throughout the world, living all through the and permafrost while foraging for plants. Pleistocene (from 2 million to 11,000 years ago) when much of Europe and North America was covered with ice. Stalking their prey silently in the open countryside until close enough to pounce, then stabbing their great dagger-like canine teeth into the ambushed victim’s neck or belly, they are believed by some to have been specially adapted for preying on mammoths. The largest and perhaps most successful of the saber-tooths, Smilodon (“Knife Tooth”) was As these creatures spread to warmer regions, also the last. It possessed a lower jaw that some of them, such as this Pleistocene dwarf could open as wide as 90 degrees. They mammoth (named for Thomas Jefferson), became extinct about 11,000 years ago, became adapted to insular isolation. When many of them lured to their deaths while sea levels rose during the interglacials, scavenging the remains of other unfortunate forming new islands as the coastal plains creatures trapped in the deadly tar pits of were flooded, large mammals, suddenly Southern California. This skull is from the isolated from predators and competing for famous Rancho La Brea deposits. Page limited food supplies, died out while the Museum. smaller ones requiring less food survived. This fossil jawbone was found on Santa 129. Order Coleoptera, Rosa Island. Private collection. Family Dytiscidae Dytiscus 128. Order Carnivora, Pleistocene California Family felidae Smilodon fatalis Late Pleistocene, California

Half of the known species of insects are beetles, whose vast varieties outnumber those of any other animal order. Their hard front wings, when folded, serve to protect their delicate, membranous hind wings. Apparently evolved from early relatives of Bulls” at Lascaux cave in France. Reindeer the cockroaches, they first appeared in the carved on a spear-thrower made of antler, as Permian and have survived relatively well as horses engraved on a perforated unchanged, rarely developing any extreme antler (presumably used for straightening specializations either structurally or in their wooden spears) may have been thought to habits. A predaceous water beetle, Dytiscus invoke the seasonal return of migratory fed by diving for its prey. prey, while carved figurines with exaggerated female features, known as Although in some groups of beetles the male Venuses, suggest the development of lives with the female and assists in caring symbolic expressions of fertility. Nearly for their young from the larval stage to 40,000 years old, this small and elegant pupation, the vigorous behavior of the carving of a wild horse was discovered in carnivorous groups precludes the gentle the cave of Vogelherd in Wurttemberg, social behavior in caring for young, whose Germany. nearly legless larvae suggest the ancestral form of these ancient creatures. Trapped in the asphalt of the Pleistocene tar pits of Southern California, these perfectly preserved Dytiscus specimens were recovered from the famous Rancho La Brea deposits. Private collection.

130. Cro-Magnon artifacts Spear point Ornamental bear claws Fishhooks Engraved reindeer antler Carved reindeer antler Mammoth carved in bone Bulls carved in bone Wild horse of Vogelherd Small Venus Late Pleistocene, Western Europe

The harpoons, spear-throwers, needles pierced with an “eye”, fishhooks, and handles invented by Cro-Magnons led the way not only to mankind’s taming of the environment, but also to the artful recording of his abstract perception of it. American Museum of Natural History.

131. Order Primates By 19,000 to 15,000 years ago, lifelike Family Hominidae representations of game painted on cave Homo sapiens sapiens walls began to appear, such as “The Hall of Middle Pleistocene, France hurling range of their spears in hunting big game and to introduce freshwater fish to their diets. Nourished by the availability of vast herds of wild game, the explosive growth of their population succeeded even in the severe arctic climate. Dated at 30,000 years and known as Cro-Magnon I, this classic skull of an elderly individual was recovered from Les Eyzies. Musee de l’Homme.

132. Venus of Willendorf Late Pleistocene, Austria

First appearing in Africa, this subspecies of wandering hunter-gatherers eventually colonized every continent except Antarctica. Interbreeding with archaic local populations throughout the world may have produced the variety of races known today. Collectively known as Cro-Magnon Man (named for fossil remains found at Cro-Magnon in southern France), this race of early Homo sapiens sapiens of 40,000 to 10,000 years ago were fully modern members of our own subspecies. Surviving the harsh climates of the Ice Age, these Late Stone Age hunters were the ancestors of present-day European Found in 1908 in the Danube Valley, Caucasoids (whites). Austria, and dated at about 40,000 years, this ancient and meticulously detailed With sophisticated and often elaborately limestone carving was probably used as a decorated implements fashioned from stone fertility fetish by Cro-Magnons. The careful and bone, Cro-Magnon culture appears to styling of its hair attests to the age of this stress hunting, as evidenced by their artful ancient practice. The tapering of the legs, paintings, engravings and sculptures of such with their missing feet, implies that it once big game animals as reindeer, oxen, and stood in a specially carved out base, horses. Advanced weapons and hunting presumably a primitive altar. Vienna methods enabled these people to double the Natural History Museum. 133. Moon Rocks feldspar that doesn’t occur on Earth), Apollo Lunar Landing Missions suggesting that the Moon was captured by Lunar crust Apollo 15 the Earth’s gravity after its formation. The “Genesis Rock” was found lying on a mountainside, undisturbed for eons, where its glittering crystals attracted the astronauts to it.

Lunar basalt Apollo 17

This black basaltic rock, similar to those found on Earth, is pitted with glassy holes left by the heat of escaping gases in the Moon’s vacuous atmospheric pressure. Mainly composed of iron and pyroxene (magnesium iron silicate) with occasional traces of calcium, this rock is evidence that the Moon’s iron core was formerly molten like the Earth’s.

Lunar basalt Apollo 12

Known as the “Genesis Rock”, this white Pitted on both sides with tiny feldspar was the first sample of lunar crust micrometeorite craters and composed used for determining the age of the Moon. primarily of iron and magnesium, this small Evidence that the Moon, like the Earth, gray basaltic rock was evidently shifted emerged from a swirling cloud of from its original position on the lunar condensing gases during the formation of surface at some point in its history. NASA the Solar System some 4.6 billion years ago, specimens courtesy of W. R. Muehlberger, its composition differs (chiefly calcium University of Texas, Austin. aluminum silicate, a form of reflective

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