Postcranial Anatomy of Haldanodon Exspectatus (Mammalia, Docodonta) from the Late Jurassic (Kimmeridgian) of Portugal and Its Bearing for Mammalian Evolution
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A Dated Phylogeny of Marsupials Using a Molecular Supermatrix and Multiple Fossil Constraints
Journal of Mammalogy, 89(1):175–189, 2008 A DATED PHYLOGENY OF MARSUPIALS USING A MOLECULAR SUPERMATRIX AND MULTIPLE FOSSIL CONSTRAINTS ROBIN M. D. BECK* School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia Downloaded from https://academic.oup.com/jmammal/article/89/1/175/1020874 by guest on 25 September 2021 Phylogenetic relationships within marsupials were investigated based on a 20.1-kilobase molecular supermatrix comprising 7 nuclear and 15 mitochondrial genes analyzed using both maximum likelihood and Bayesian approaches and 3 different partitioning strategies. The study revealed that base composition bias in the 3rd codon positions of mitochondrial genes misled even the partitioned maximum-likelihood analyses, whereas Bayesian analyses were less affected. After correcting for base composition bias, monophyly of the currently recognized marsupial orders, of Australidelphia, and of a clade comprising Dasyuromorphia, Notoryctes,and Peramelemorphia, were supported strongly by both Bayesian posterior probabilities and maximum-likelihood bootstrap values. Monophyly of the Australasian marsupials, of Notoryctes þ Dasyuromorphia, and of Caenolestes þ Australidelphia were less well supported. Within Diprotodontia, Burramyidae þ Phalangeridae received relatively strong support. Divergence dates calculated using a Bayesian relaxed molecular clock and multiple age constraints suggested at least 3 independent dispersals of marsupials from North to South America during the Late Cretaceous or early Paleocene. Within the Australasian clade, the macropodine radiation, the divergence of phascogaline and dasyurine dasyurids, and the divergence of perameline and peroryctine peramelemorphians all coincided with periods of significant environmental change during the Miocene. An analysis of ‘‘unrepresented basal branch lengths’’ suggests that the fossil record is particularly poor for didelphids and most groups within the Australasian radiation. -
April Isch Neander
February 2017 Curriculum Vitae April Isch Neander Scientific Illustrator University of Chicago Department of Organismal Biology and Anatomy 1027 E 57th Street Anatomy 306 Chicago, IL 60637 [email protected] 773.702.4715 Education M.S. Biomedical Visualization, University of Illinois at Chicago, 2012 Graduate Research Project: Visualizing the Parasagittal Step Cycle of Kryptobaatar dashzevegi, a Multituberculate with Transitional Shoulder Girdle. B.A. Biology, University of Vermont, 2010 Minor in Studio Art Publications Published Art and Illustrations Luo, Z. X., Schultz, J. A., & Ekdale, E. G. (2016). Evolution of the Middle and Inner Ears of Mammaliaforms: The Approach to Mammals. In Evolution of the Vertebrate Ear (pp. 139-174). Springer International Publishing. Brusatte, S., Luo, Z. X. (2016, June). Ascent of the Mammals. Scientific American, 30-35. Luo, Z. X., Gatesy, S. M., Jenkins, F. A., Amaral, W. W., & Shubin, N. H. (2015). Mandibular and dental characteristics of Late Triassic mammaliaform Haramiyavia and their ramifications for basal mammal evolution. Proceedings of the National Academy of Sciences, 112(51), E7101-E7109. Chang, Kenneth. (2015, November 16). Jawbone in Rock May Clear Up a Mammal Family Mystery. The New York Times. Hopson, James A. (2015). Fossils, Trackways, and Transitions in Locomotion. In Dial, Kenneth P., Neil Shubin, and Elizabeth L. Brainerd, eds. Great transformations in vertebrate evolution (pp. 125-141). University of Chicago Press. Luo, Z. X., Meng, Q. J., Ji, Q., Liu, D., Zhang, Y. G., & Neander, A. I. (2015). Evolutionary development in basal mammaliaforms as revealed by a docodontan. Science, 347(6223), 760-764. Meng, Q. J., Ji, Q., Zhang, Y. -
The Mammary Gland and Its Origin During Synapsid Evolution
P1: GMX Journal of Mammary Gland Biology and Neoplasia (JMGBN) pp749-jmgbn-460568 January 9, 2003 17:51 Style file version Nov. 07, 2000 Journal of Mammary Gland Biology and Neoplasia, Vol. 7, No. 3, July 2002 (C 2002) The Mammary Gland and Its Origin During Synapsid Evolution Olav T. Oftedal1 Lactation appears to be an ancient reproductive trait that predates the origin of mammals. The synapsid branch of the amniote tree that separated from other taxa in the Pennsylva- nian (>310 million years ago) evolved a glandular rather than scaled integument. Repeated radiations of synapsids produced a gradual accrual of mammalian features. The mammary gland apparently derives from an ancestral apocrine-like gland that was associated with hair follicles. This association is retained by monotreme mammary glands and is evident as ves- tigial mammary hair during early ontogenetic development of marsupials. The dense cluster of mammo-pilo-sebaceous units that open onto a nipple-less mammary patch in monotremes may reflect a structure that evolved to provide moisture and other constituents to permeable eggs. Mammary patch secretions were coopted to provide nutrients to hatchlings, but some constituents including lactose may have been secreted by ancestral apocrine-like glands in early synapsids. Advanced Triassic therapsids, such as cynodonts, almost certainly secreted complex, nutrient-rich milk, allowing a progressive decline in egg size and an increasingly altricial state of the young at hatching. This is indicated by the very small body size, presence of epipubic bones, and limited tooth replacement in advanced cynodonts and early mammali- aforms. Nipples that arose from the mammary patch rendered mammary hairs obsolete, while placental structures have allowed lactation to be truncated in living eutherians. -
Using Dental Enamel Wrinkling to Define Sauropod Tooth Morphotypes from the Cañadón Asfalto Formation, Patagonia, Argentina
RESEARCH ARTICLE Using Dental Enamel Wrinkling to Define Sauropod Tooth Morphotypes from the Cañadón Asfalto Formation, Patagonia, Argentina Femke M. Holwerda1,2,3*, Diego Pol4,5, Oliver W. M. Rauhut1,3 1 Staatliche Naturwissenschaftliche Sammlungen Bayerns (SNSB), Bayerische Staatssammlung für Paläontologie und Geologie, München, Germany, 2 GeoBioTec, Departamento de Ciências da Terra, Faculdade de Ciências e Tecnologia (FCT), Universidade Nova de Lisboa, Caparica, Portugal, 3 Department of Earth and Environmental Sciences and GeoBioCenter, Ludwig Maximilians Universität, München, Germany, 4 Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina, 5 Museo Paleontológico Egidio Feruglio, Trelew, Argentina * [email protected] Abstract OPEN ACCESS The early Middle Jurassic is regarded as the period when sauropods diversified and be- Citation: Holwerda FM, Pol D, Rauhut OWM (2015) came major components of the terrestrial ecosystems. Not many sites yield sauropod mate- Using Dental Enamel Wrinkling to Define Sauropod Tooth Morphotypes from the Cañadón Asfalto rial of this time; however, both cranial and postcranial material of eusauropods have been Formation, Patagonia, Argentina. PLoS ONE 10(2): found in the Cañadón Asfalto Formation (latest Early Jurassic–early Middle Jurassic) in e0118100. doi:10.1371/journal.pone.0118100 Central Patagonia (Argentina), which may help to shed light on the early evolution of Academic Editor: Peter Dodson, University of eusauropods. These eusauropod remains include teeth associated with cranial and man- Pennsylvania, UNITED STATES dibular material as well as isolated teeth found at different localities. In this study, an assem- Received: September 1, 2014 blage of sauropod teeth from the Cañadón Asfalto Formation found in four different Accepted: January 7, 2015 localities in the area of Cerro Condor (Chubut, Argentina) is used as a mean of assessing sauropod species diversity at these sites. -
Constraints on the Timescale of Animal Evolutionary History
Palaeontologia Electronica palaeo-electronica.org Constraints on the timescale of animal evolutionary history Michael J. Benton, Philip C.J. Donoghue, Robert J. Asher, Matt Friedman, Thomas J. Near, and Jakob Vinther ABSTRACT Dating the tree of life is a core endeavor in evolutionary biology. Rates of evolution are fundamental to nearly every evolutionary model and process. Rates need dates. There is much debate on the most appropriate and reasonable ways in which to date the tree of life, and recent work has highlighted some confusions and complexities that can be avoided. Whether phylogenetic trees are dated after they have been estab- lished, or as part of the process of tree finding, practitioners need to know which cali- brations to use. We emphasize the importance of identifying crown (not stem) fossils, levels of confidence in their attribution to the crown, current chronostratigraphic preci- sion, the primacy of the host geological formation and asymmetric confidence intervals. Here we present calibrations for 88 key nodes across the phylogeny of animals, rang- ing from the root of Metazoa to the last common ancestor of Homo sapiens. Close attention to detail is constantly required: for example, the classic bird-mammal date (base of crown Amniota) has often been given as 310-315 Ma; the 2014 international time scale indicates a minimum age of 318 Ma. Michael J. Benton. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Philip C.J. Donoghue. School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, U.K. [email protected] Robert J. -
Width Measured at the Level of Anterior Squamosal/Parietal Suture
Fig. 5. (A) Scaling of brain vault size (width measured at the level of anterior squamosal/parietal suture) relative to skull size (measured at the distance between the left versus right temporomandibular joints). This shows that allometry of small size of Hadrocodium, by itself, is not sufficient to account for its very large braincase. Had-rocodium's brain vault is larger (wider) than expected for the crown-group mammals with similar skull width from the allometrical regression. By contrast, all contemporaneous mammaliaforms (triangles: Sinoconodon, Morganucodon, and Haldanodon) with the postdentary trough and meckelian groove have smaller (narrower) brain vaults than those living mammal taxa (and Hadrocodium) of comparable skull size. The brain vault is narrower in nonmammaliaform cynodonts (squares: Chaliminia, Massetoganthus, Probelesodon, Probainognathus, and Yunnanodon) than in mammaliaform stem taxa and much narrower than expected for crown group mammals of similar size. The allometric equation (natural logarithmic scale) for the brain vault width (Y) to the skull width at the level of TMJ (X) for species in the mammalian crown groups (circles: 37 living and 8 fossil species): Y =0.98X -0.31 (R2 – 0.715). Data from cynodonts, mammaliaforms, and Hadrocodium are added second arily for comparison with the regression of extant and fossil species of mammalian crown group. (B) Estimated body-size distributions of mammaliaform insectivores in the Early Jurassic Lufeng fauna [following method of Gingerich (50)]. The estimated 2-g body mass of Hadrocodium is in strong contrast to its contemporary mammaliaforms of the Late Triassic and Early Jurassic, such as Sinconodon (from ~13 to ~517 g, based on skull length from 22 to 62 mm) and Morganucodon (from 27 to 89 g, based on skull length from 27 to 38 mm). -
The Mesozoic Era Alvarez, W.(1997)
Alles Introductory Biology: Illustrated Lecture Presentations Instructor David L. Alles Western Washington University ----------------------- Part Three: The Integration of Biological Knowledge Vertebrate Evolution in the Late Paleozoic and Mesozoic Eras ----------------------- Vertebrate Evolution in the Late Paleozoic and Mesozoic • Amphibians to Reptiles Internal Fertilization, the Amniotic Egg, and a Water-Tight Skin • The Adaptive Radiation of Reptiles from Scales to Hair and Feathers • Therapsids to Mammals • Dinosaurs to Birds Ectothermy to Endothermy The Evolution of Reptiles The Phanerozoic Eon 444 365 251 Paleozoic Era 542 m.y.a. 488 416 360 299 Camb. Ordov. Sil. Devo. Carbon. Perm. Cambrian Pikaia Fish Fish First First Explosion w/o jaws w/ jaws Amphibians Reptiles 210 65 Mesozoic Era 251 200 180 150 145 Triassic Jurassic Cretaceous First First First T. rex Dinosaurs Mammals Birds Cenozoic Era Last Ice Age 65 56 34 23 5 1.8 0.01 Paleo. Eocene Oligo. Miocene Plio. Ple. Present Early Primate First New First First Modern Cantius World Monkeys Apes Hominins Humans A modern Amphibian—the toad A modern day Reptile—a skink, note the finely outlined scales. A Comparison of Amphibian and Reptile Reproduction The oldest known reptile is Hylonomus lyelli dating to ~ 320 m.y.a.. The earliest or stem reptiles radiated into therapsids leading to mammals, and archosaurs leading to all the other reptile groups including the thecodontians, ancestors of the dinosaurs. Dimetrodon, a Mammal-like Reptile of the Early Permian Dicynodonts were a group of therapsids of the late Permian. Web Reference http://www.museums.org.za/sam/resource/palaeo/cluver/index.html Therapsids experienced an adaptive radiation during the Permian, but suffered heavy extinctions during the end Permian mass extinction. -
Mammals from the Mesozoic of Mongolia
Mammals from the Mesozoic of Mongolia Introduction and Simpson (1926) dcscrihed these as placental (eutherian) insectivores. 'l'he deltathcroids originally Mongolia produces one of the world's most extraordi- included with the insectivores, more recently have narily preserved assemblages of hlesozoic ma~nmals. t)een assigned to the Metatheria (Kielan-Jaworowska Unlike fossils at most Mesozoic sites, Inany of these and Nesov, 1990). For ahout 40 years these were the remains are skulls, and in some cases these are asso- only Mesozoic ~nanimalsknown from Mongolia. ciated with postcranial skeletons. Ry contrast, 'I'he next discoveries in Mongolia were made by the Mesozoic mammals at well-known sites in North Polish-Mongolian Palaeontological Expeditions America and other continents have produced less (1963-1971) initially led by Naydin Dovchin, then by complete material, usually incomplete jaws with den- Rinchen Barsbold on the Mongolian side, and Zofia titions, or isolated teeth. In addition to the rich Kielan-Jaworowska on the Polish side, Kazi~nierz samples of skulls and skeletons representing Late Koualski led the expedition in 1964. Late Cretaceous Cretaceous mam~nals,certain localities in Mongolia ma~nmalswere collected in three Gohi Desert regions: are also known for less well preserved, but important, Bayan Zag (Djadokhta Formation), Nenlegt and remains of Early Cretaceous mammals. The mammals Khulsan in the Nemegt Valley (Baruungoyot from hoth Early and Late Cretaceous intervals have Formation), and llcrmiin 'ISav, south-\vest of the increased our understanding of diversification and Neniegt Valley, in the Red beds of Hermiin 'rsav, morphologic variation in archaic mammals. which have heen regarded as a stratigraphic ecluivalent Potentially this new information has hearing on the of the Baruungoyot Formation (Gradzinslti r't crl., phylogenetic relationships among major branches of 1977). -
Femur of a Morganucodontid Mammal from the Middle Jurassic of Central Russia
Femur of a morganucodontid mammal from the Middle Jurassic of Central Russia PETR P. GAMBARYAN and ALEXANDER 0.AVERIANOV Gambaryan, P.P. & Averianov, A.O. 2001. Femur of a morganucodontid mammal from the Middle Jurassic of Central Russia. -Acta Palaeontologica Polonica 46,1,99-112. We describe a nearly complete mammalian femur from the Middle Jurassic (upper Bathonian) from Peski quarry, situated some 100 km south east of Moscow, central Rus- sia. It is similar to the femora of Morganucodontidae in having a globular femoral head, separated from the greater trochanter and reflected dorsally, fovea capitis present, both trochanters triangular and located on the same plane, distal end flat, mediolaterally expanded, and somewhat bent ventrally, and in the shape and proportions of distal condyles. It is referred to as Morganucodontidae gen. et sp. indet. It is the first representa- tive of this group of mammals in Eastern Europe from the third Mesozoic mammal local- ity discovered in Russia. Exquisite preservation of the bone surface allowed us to recon- struct partial hind limb musculature. We reconstruct m. iliopsoas as inserting on the ridge, which starts at the lesser trochanter and extends along the medial femoral margin for more than half of the femur length. On this basis we conclude that the mode of loco- motion of the Peski morganucodontid was similar to that of modern echidnas. During the propulsive phase the femur did not retract and the step elongation was provided by pronation of the femur. Key words : Mammalia, Morganucodontidae, femur, anatomy, locomotion, Jurassic, Russia. Petr P. Gambaryan [[email protected]] and Alexander 0. -
Lower Triassic Postcanine Teeth with Allotherian-Like Crowns
Research Letters South African Journal of Science 103, May/June 2007 245 Lower Triassic postcanine teeth with allotherian-like crowns F. Abdala*‡, H. Mocke*§ and P.J. Hancox* The Allotheria are fossil mammals with upper and lower post- canines usually showing two longitudinal rows of cusps separated by a central valley. The group comprises the poorly known haramiyids, mostly represented by isolated teeth, and the notably diverse and long-lived multituberculates; its monophyly is uncer- tain. The oldest records of this particular group are the Late Triassic (Norian–Rhaetian) haramiyids. We present here postcanines with haramiyid-like crowns that were recovered from the Lower Triassic of South Africa. A distinguishing feature of the new teeth is that they are single-rooted. This is the oldest record of mammal-like teeth with crowns having parallel rows of cusps, representing a temporal extension of some 43 million years from similar crown patterns of haramiyids and tritylodontids. This finding reinforces evidence of the remarkable faunal turnover of therapsids in the Early/Middle Triassic, at which time an explosive origin followed by a rapid early diversification of herbivorous/omnivorous forms with occluding expanded postcanines took place. Introduction The Beaufort Group of the South African Karoo shows an abundance and diversity of non-mammalian synapsids, which have allowed for biostratigraphic subdivisions ranging from Middle Permian to Middle Triassic.1 The youngest of these Fig. 1.Allotherian-like teeth.A, Occlusal and lateral views of BP/1/6515 (Pattern 1); B, occlusal and lateral views of BP/1/6516 (Pattern 2). biozones, the Cynognathus Assemblage Zone (AZ), comprises the full extent of the Burgersdorp Formation of the Tarkastad Sub- found to be most parsimonious from an unconstrained search, group (J. -
Early Cretaceous Amphilestid ('Triconodont') Mammals from Mongolia
Early Cretaceous amphilestid ('triconodont') mammals from Mongolia ZOFIAKIELAN-JAWOROWSKA and DEMBERLYIN DASHZEVEG Kielan-Jaworowską Z. &Daslueveg, D. 1998. Early Cretaceous amphilestid (.tricono- dont') mammals from Mongotia. - Acta Pal.aeontol.ogicaPolonica,43,3, 413438. Asmall collection of ?Aptianor ?Albian amphilestid('triconodont') mammals consisting of incomplete dentaries and maxillae with teeth, from the Khoboor localiĘ Guchin Us counĘ in Mongolia, is described. Grchinodon Troftmov' 1978 is regarded a junior subjective synonym of GobiconodonTroftmov, 1978. Heavier wear of the molariforms M3 andM4than of themore anteriorone-M2 in Gobiconodonborissiaki gives indirect evidence formolariformreplacement in this taxon. The interlocking mechanismbetween lower molariforms n Gobiconodon is of the pattern seen in Kuchneotherium and Ttnodon. The ińterlocking mechanism and the type of occlusion ally Amphilestidae with Kuehneotheriidae, from which they differ in having lower molariforms with main cusps aligned and the dentary-squamosal jaw joint (double jaw joint in Kuehneotheńdae). The main cusps in upper molariforms M3-M5 of Gobiconodon, however, show incipient tńangular arrangement. The paper gives some support to Mills' idea on the therian affinities of the Amphilestidae, although it cannot be excluded that the characters that unite the two groups developed in parallel. Because of scanty material and arnbiguĘ we assign the Amphilestidae to order incertae sedis. Key words : Mammali4 .triconodonts', Amphilestidae, Kuehneotheriidae, Early Cretaceous, Mongolia. Zofia Kiel,an-Jaworowska [zkielnn@twarda,pan.pl], InsĘtut Paleobiologii PAN, ul. Twarda 5 I /5 5, PL-00-8 I 8 Warszawa, Poland. DemberĘin Dash7eveg, Geological Institute, Mongolian Academy of Sciences, Ulan Bator, Mongolia. Introduction Beliajeva et al. (1974) reportedthe discovery of Early Cretaceous mammals at the Khoboor locality (referred to also sometimes as Khovboor), in the Guchin Us Soinon (County), Gobi Desert, Mongolia. -
A New Mammaliaform from the Early Jurassic and Evolution Of
R EPORTS tary trough with a shelflike dorsal medial ridge, and all other nonmammalian mamma- A New Mammaliaform from the liaforms have a medial concavity on the man- dibular angle (8–14, 23), as in nonmamma- Early Jurassic and Evolution of liaform cynodonts (9, 14, 24–27). The post- dentary trough and the medial concavity on Mammalian Characteristics the mandibular angle respectively accommo- dated the prearticular/surangular and the re- Zhe-Xi Luo,1* Alfred W. Crompton,2 Ai-Lin Sun3 flected lamina of the angular (9, 25–27) that are the homologs to the mammalian middle A fossil from the Early Jurassic (Sinemurian, ϳ195 million years ago) represents ear bones (9, 14, 16–21, 23, 26). The absence a new lineage of mammaliaforms, the extinct groups more closely related to of these structures indicates that the postden- the living mammals than to nonmammaliaform cynodonts. It has an enlarged tary bones (“middle ear ossicles”) must have cranial cavity, but no postdentary trough on the mandible, indicating separation been separated from the mandible (Fig. 3). of the middle ear bones from the mandible. This extends the earliest record of Hadrocodium lacks the primitive meckelian these crucial mammalian features by some 45 million years and suggests that sulcus of the mandible typical of all nonmam- separation of the middle ear bones from the mandible and the expanded brain maliaform cynodonts (24–27), stem groups vault could be correlated. It shows that several key mammalian evolutionary of mammaliaforms (8, 9, 14, 23, 26, 27), innovations in the ear region, the temporomandibular joint, and the brain vault triconodontids (28, 29), and nontribosphenic evolved incrementally through mammaliaform evolution and long before the therian mammals (30).