Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Komodo dragon (Varanus komodoensis) Phylum Chordata Subphylum Vertebrata Class Reptilia Order Squamata Family Varanidae Varanus komodoensis feeding on water buffalo (Wikipedia) Varanus salvator CT scan from DigiMorph Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 BBC Video “Komodo Dragons attack” https://www.youtube.com/watch?v=gcTg9mt4eAk Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Komodo dragon (Varanus komodoensis) CT scans available from http://www.digimorph.org/ Parietal Frontal Nasal Lach- rymal Pre- Maxilla Jugal maxilla Quadrate Articular Surangular Dentary Angular Varanus salvator CT scan from DigiMorph Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Jaw muscles and movements in a lizard Black and white tegu (Tupinambis merianae) Phylum Chordata Subphylum Vertebrata Class Reptilia Order Squamata Family Teiidae Tupinambis merianae jaw musculature (from Gröning et al. 2013) Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Characteristics of the reptilian bite 1. Jaw joint is located between quadrate and articular bones 2. Lower jaw pivots around end of quadrate like upside down see-saw 3. Posterior muscles pull up on back “handle” of the articular to open jaw 4. Anterior muscles pull up on surangular and other bones to close jaw 5. Muscles originate around temporal openings and insert on jaw Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Phylogeny of Living Vertebrates Chondrichthyes “Osteichthyes” Agnatha Amphibia Crocodilia Sharks, rays and Ray-finned and lobe- Frogs, Mammalia Chelonia Lepidosauria Lampreys and Alligators, Class Aves chimaeras finned fish salamanders Mammals Turtles Lizards, snakes hagfish crocodiles Birds Archosauria Diapsida Reptilia Amniota Tetrapoda Vertebrata Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Synapomorphies (shared derived features) of vertebrates • Bilateral symmetry • Mouth, stomach, and gut • Brain and spinal cord (CNS, central nervous system) • Head with multiple sense organs • Heart and circulatory system ventral to CNS • Pharyngeal pouches (gill arches) • Segmented body with muscles • Skeleton composed of cartilage or bone (collagen with hydroxyapatite mineral), dentine, and enamel • Paired appendages Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Era Period Epoch Age (millions of years ago) Holocene Quaternary Pleistocene Mass Extinction 2.6 Pliocene Neogene Miocene 23 Oligocene Cenozoic Eocene Paleogene Paleocene 65 Cretaceous 145 Jurassic 199 Mesozoic Triassic Phanerozoic 251 Permian 299 Pennsylvanian 318 fish tetrapods and Jawed Mississippian Carboniferous 359 Devonian Early tetrapods on land 416 Paleozoic Conodonts Silurian 444 Ordovician fish Jawless 488 Cambrian First vertebrate fossils 542 Proterozoic 2.5 billion Archean 4.6 billion Precambrian Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Early Paleozoic (542- 359 Ma) •North America was much smaller than today •Sea level was high, with extensive shallow seas •Oldest parts of the Appalachian Mountains were just forming Early tetrapods on land First vertebrates Hallam, 1984. Annual Review of Earth and Planetary Sciences, 12: 205-243. (c) Ron Blakey (http://jan.ucc.nau.edu/~rcb7/nam.html) Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Early Cambrian (540 Ma) North China South China Gondwana Siberia North (Africa + South America America + Australia + Antarctica) Baltica (c) Ron Blakey (http://jan.ucc.nau.edu/~rcb7/nam.html) Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Early Cambrian (540 Ma) North China South China Gondwana Siberia North (Africa + South America America + Australia + Antarctica) Baltica (c) Ron Blakey (http://jan.ucc.nau.edu/~rcb7/nam.html) Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Chengjiang, China (Early Cambrian, 520-525 Ma) Haikouichthys • Mouth and gut tube • Dorsal fin Earliest vertebrate • Myotomes (muscle segments) • Gill pouches • Notochord • Heart • Nasal and otic capsules Shu et al., 1999, Nature, 402: 42-46, Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Chengjiang, China (Early Cambrian, 520-525 Ma) Haikouichthys • Mouth and gut tube • Dorsal fin Earliest vertebrate • Myotomes (muscle segments) • Gill pouches • Notochord • Heart • Nasal and otic capsules Shu et al., 1999, Nature, 402: 42-46, Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Conodonts Cambrian to Triassic • Tiny early vertebrates • Phosphatic tooth elements are commonly preserved as fossils • Whole animal extremely rare (no bony skeleton) • Phosphatic material changes color with heat, used as “paleothermometer” to study metamorphism and burial of rock • Biostratigraphic markers Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Conodont elements (“teeth”) in life position Pandorinellina remscheidensis elements and reconstruction their position in a living animal (Aldridge and Purnell, 1996. The conodont controversies. TREE, 11: 463-468) Manticolepis subrecta apparatus in life position (Dzik, 1991, Evolution of oral apparatuses in the conodont chordates. Acta Palaeontologica Polonica, 36: 265-323) Department of Geological Sciences | Indiana University Dinosaurs and their relatives (c) 2015, P. David Polly Geology G114 Phylogeny of early vertebrates Agnatha, “jawless fish” (paraphyletic) “jawed fish” Hagfish Lampreys Haikouichtyes Conodonts Heterostraci Anaspida Osteostraci Gnathostomes * jaws Unnamed * paired fins or fin folds Unnamed * calcified dermal skeleton Craniata * eye muscles * symmetrical gills * 2 semicircular canals Vertebrata.