A Fresh Approach to Stellar Benchmarking
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213 a New Haramiyid Indicating a Complex Pattern of Evolution In
Vol.27 No.4 2013 Science Watch A New Haramiyid Indicating a Complex Pattern of Evolution in Mesozoic Mammals Earth Science major unsolved problem in mammalian evolution is University reported a new haramiyid from the Jurassic period the origin of Allotheria, including Multituberculata of China, Arboroharamiya jenkinsi, a partial skeleton with A and Haramiyida. Multituberculates are the most both mandibles associated with teeth and isolated upper teeth. diverse and best known Mesozoic era mammals and This largest known haramiyid reveals additional mammalian ecologically resemble rodents, but haramiyids are known features of this group, and helps to identify other haramiyids mainly from isolated teeth, hampering our search for their represented by isolated teeth, indicating a complex pattern phylogenetic relationships. Researchers from the Institute of evolution involving many convergences and/or reversals of Vertebrate Paleontology and Paleoanthropology (IVPP), existed in Mesozoic mammals, as reported August 8 in CAS, the Shandong Tianyu Museum of Nature and the Linyi Nature. Reconstruction of Arboroharamiya jenkinsi. (Image by BI Shundong) Bulletin of the Chinese Academy of Sciences 213 BCAS Vol.27 No.4 2013 The new specimen was unearthed from the Middle–Late Jurassic Tiaojishan Formation in the town of Mutoudeng, Qinglong County, Hebei Province, China, dated about 160 million years. Researchers said it is the largest known haramiyid with a body mass estimated at 354 grams. Arboroharamiya, as with other mammals, has body Earth Science hair (preserved as impressions), a single-boned (dentary) mandible that implies a three-boned middle ear. The dentition is differentiated into incisors and multi-rooted premolars and molars, with the canine presumably lost. -
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. -
Evidence of Diphyodonty and Heterochrony for Dental
第57卷 第1期 古 脊 椎 动 物 学 报 pp. 51–76 2019年1月 VERTEBRATA PALASIATICA figs. 1–9 DOI: 10.19615/j.cnki.1000-3118.180803 Evidence of diphyodonty and heterochrony for dental development in euharamiyidan mammals from Jurassic Yanliao Biota MAO Fang-Yuan1,2 ZHENG Xiao-Ting3,4 WANG Xiao-Li3,4 WANG Yuan-Qing1,2 BI Shun-Dong5 MENG Jin6,1 (1 Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044, China) (2 CAS Center for Excellence in Life and Paleoenvironment Beijing 100044, China [email protected]) (3 Institute of Geology and Paleontology, Linyi University Linyi, Shandong 276005, China) (4 Shandong Tianyu Museum of Nature Pingyi, Shandong 273300, China) (5 Department of Biology, Indiana University of Pennsylvania Indiana 15705, USA) (6 Division of Paleontology, American Museum of Natural History New York 10024, USA) Abstract Evidences for tooth replacement of known euharamiyidans are reported based on eight specimens of four species from the Jurassic Yanliao Biota, Liaoning Province, China. Tooth morphologies, eruptional and wear condition, and tooth germs are directly observed and/or revealed by Micro CT or slab CL scan. The euharamiyidan dentition has definite number of cheek teeth and monophyodont molars that are related to precise occlusion. Incisor germs are found in three specimens of Arboroharamiya but not in Shenshou lui and Xianshou linglong. The incisor germs in the upper jaw, presumably I2, have a large crown with two or three cusps; those in the lower jaw, interpreted as the permanent i2, are positioned dorsal to the root of the erupted incisor, interpreted as di2. -
Researchers Discover Three Extinct Squirrel-Like Species
Media Inquiries: Kendra Snyder, Department of Communications 212-496-3419; [email protected] www.amnh.org _____________________________________________________________________________________ September 10, 2014 RESEARCHERS DISCOVER THREE EXTINCT SQUIRREL-LIKE SPECIES FINDINGS SUPPORT EARLIER ORIGIN OF MAMMALS, IN LATE TRIASSIC Paleontologists have described three new small squirrel-like species that place a poorly understood Mesozoic group of animals firmly in the mammal family tree. The study, led by scientists at the American Museum of Natural History and the Chinese Academy of Sciences, supports the idea that mammals—an extremely diverse group that includes egg-laying monotremes such as the platypus, marsupials such as the opossum, and placentals like humans and whales—originated at least 208 million years ago in the late Triassic, much earlier than some previous research suggests. The study is published today in the journal Nature. “For decades, scientists have been debating whether the extinct group, called Haramiyida, belongs within or outside of Mammalia,” said co-author Jin Meng, a curator in the Museum’s Division of Paleontology. “Previously, everything we knew about these animals was based on fragmented jaws and isolated teeth. But the new specimens we discovered are extremely well preserved. And based on these fossils, we now have a good idea of what these animals really looked like, which confirms that they are, indeed, mammals.” The three new species—Shenshou lui, Xianshou linglong, and Xianshou songae—are described from six nearly complete 160-million-year-old fossils found in China. The animals, which researchers have placed in a new group, or clade, called Euharamiyida, likely looked similar to small squirrels. -
Bayesian Tip-Dated Phylogenetics: Topological Effects, Stratigraphic Fit
bioRxiv preprint doi: https://doi.org/10.1101/533885; this version posted January 29, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. 1 Bayesian Tip-dated Phylogenetics: Topological Effects, 2 Stratigraphic Fit and the Early Evolution of Mammals 3 Benedict King1,2,* and Robin Beck3 4 1 Naturalis Biodiversity Center, Leiden, the Netherlands. 2 College of Science and Engineering, 5 Flinders University, Adelaide, South Australia 5042, Australia. 3School of Environmental & Life 6 Sciences, University of Salford, Salford M5 4WT, UK 7 *Corresponding author email: [email protected] 8 9 ABSTRACT 10 The incorporation of stratigraphic data into phylogenetic analysis has a long history of debate, but is 11 not currently standard practice for palaeontologists. Bayesian tip-dating (or morphological clock) 12 phylogenetic methods have returned these arguments to the spotlight, but how tip-dating affects 13 the recovery of evolutionary relationships has yet to be fully explored. Here we show, through 14 analysis of several datasets with multiple phylogenetic methods, that topologies produced by tip- 15 dating are outliers when compared to topologies produced by parsimony and undated Bayesian 16 methods, which retrieve broadly similar trees. Unsurprisingly, trees recovered by tip-dating have 17 better fit to stratigraphy than trees recovered by other methods, due to trees with better 18 stratigraphic fit being assigned a higher prior probability. Differences in stratigraphic fit and tree 19 topology between tip-dating and other methods appear to be concentrated in parts of the tree with 20 weaker character signal and a stronger influence of the prior, as shown by successive deletion of the 21 most incomplete taxa from a sauropod dataset. -
New Multituberculate Teeth from the Early Cretaceous of Morocco
New multituberculate teeth from the Early Cretaceous of Morocco GERHARD HAHN and RENATE HAHN Hahn, G. and Hahn, R. 2003. New multituberculate teeth from the Early Cretaceous of Morocco. Acta Palaeontologica Polonica 48 (3): 349–356. Three new multituberculate teeth are described from the Early Cretaceous of Morocco. Denisodon moroccensis gen. et sp. nov. is established for a second lower molar which differs from that of Hahnodon taqueti, from the same locality, by a preserved posterior buccal cusp, a smaller posterior lingual cusp and the less indented lingual wall of the crown. The sec− ond tooth is a posterior upper premolar. It is represented by the posterior portion of its crown on which is present only one row of cusps, similar to the conditions in Kielanodon, Eobaatar, Bolodon, and the Pinheirodontidae. The third tooth is a lower incisor, similar to that in Kuehneodon. Both teeth are grouped as „Hahnodontidae, gen. et sp. indet.” Paulchof− fatioidea new superfamily is established for the Paulchoffatiidae, Hahnodontidae, and Pinheirodontidae. It is character− ized by the following autapomorphies: premolarisation of I2−C, presence of a third row of cusps on the posterior upper premolars and the basin−like structure of the m2. Hahnodontidae and Hahnodon are redefined. Key words: Mammalia, Multituberculata, Paulchoffatioidea, Denisodon, Early Cretaceous, Morocco. Gerhard Hahn and Renate Hahn [[email protected]], Berliner Strasse 31, D−35282 Rauschenberg; Germany. Introduction Anoual fauna stands in stark contrast to their abundance in penecontemporaneous Laurasian faunas. Usually, remains Remains of multituberculates are very rare fossils in the of multituberculates are, as rodents today, abundant in the Gondwana area. -
Jaw Shape and Mechanical Advantage Are Indicative of Diet in Mesozoic Mammals ✉ Nuria Melisa Morales-García 1 , Pamela G
ARTICLE https://doi.org/10.1038/s42003-021-01757-3 OPEN Jaw shape and mechanical advantage are indicative of diet in Mesozoic mammals ✉ Nuria Melisa Morales-García 1 , Pamela G. Gill1,2, Christine M. Janis 1,3 & Emily J. Rayfield 1 Jaw morphology is closely linked to both diet and biomechanical performance, and jaws are one of the most common Mesozoic mammal fossil elements. Knowledge of the dietary and functional diversity of early mammals informs on the ecological structure of palaeo- communities throughout the longest era of mammalian evolution: the Mesozoic. Here, we analyse how jaw shape and mechanical advantage of the masseter (MAM) and temporalis (MAT) muscles relate to diet in 70 extant and 45 extinct mammals spanning the Late 1234567890():,; Triassic-Late Cretaceous. In extant mammals, jaw shape discriminates well between dietary groups: insectivores have long jaws, carnivores intermediate to short jaws, and herbivores have short jaws. Insectivores have low MAM and MAT, carnivores have low MAM and high MAT, and herbivores have high MAM and MAT. These traits are also informative of diet among Mesozoic mammals (based on previous independent determinations of diet) and set the basis for future ecomorphological studies. 1 School of Earth Sciences, Wills Memorial Building, University of Bristol, Bristol, UK. 2 Department of Earth Sciences, Natural History Museum, London, UK. ✉ 3 Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USA. email: [email protected] COMMUNICATIONS BIOLOGY | (2021) 4:242 | https://doi.org/10.1038/s42003-021-01757-3 | www.nature.com/commsbio 1 ARTICLE COMMUNICATIONS BIOLOGY | https://doi.org/10.1038/s42003-021-01757-3 ur understanding of Mesozoic mammals has dramatically metric) has been used as a proxy for prey choice and feeding improved in the past three decades. -
The Earliest-Known Mammaliaform Fossil from Greenland Sheds Light on Origin of Mammals
The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals Tomasz Suleja, Grzegorz Krzesinski b,1, Mateusz Tałandac, Andrzej S. Wolniewicza,d,Błazej_ Błazejowski_ a, Niels Bondee,f, Piotr Gutowskig, Maksymilian Sienkiewiczb, and Grzegorz Niedzwiedzkih,2 aInstitute of Paleobiology, Polish Academy of Sciences, 00-818 Warsaw, Poland; bFaculty of Power and Aeronautical Engineering, Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology, 00-665 Warsaw, Poland; cDepartment of Paleobiology and Evolution, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, 02-089 Warsaw, Poland; dDepartment of Earth Sciences, University of Oxford, OX1 3AN Oxford, United Kingdom; eGeological Section, Natural History Museum of Denmark, University of Copenhagen, DK-2100 Copenhagen, Denmark; fFur Museum, 7884 Fur, Denmark; gDepartment of Cranio-Maxillofacial Surgery, Oral Surgery and Implantology, Medical University of Warsaw, 02-091 Warsaw, Poland; and hDepartment of Organismal Biology, Evolutionary Biology Centre, Uppsala University, 752 36 Uppsala, Sweden Edited by Zhe-Xi Luo, The University of Chicago, Chicago, IL, and accepted by Editorial Board Member David Jablonski August 29, 2020 (received for review June 16, 2020) Synapsids are unique in having developed multirooted teeth and fossils are from the latest Norian and Rhaetian (Late Triassic), complex occlusions. These innovations evolved in at least two and are represented by isolated teeth (10), incomplete cranial or lineages of mammaliamorphs (Tritylodontidae and Mammalia- jaw remains, and postcranial elements (3). Significant differences formes). Triassic fossils demonstrate that close to the origins of between the earliest haramiyidans and other contemporary mammals, mammaliaform precursors were “experimenting” with clades of mammaliaforms have complicated the problem of tooth structure and function, resulting in novel patterns of occlu- haramiyidan ancestry and their purported relationships to other sion. -
In Quest for a Phylogeny of Mesozoic Mammals
In quest for a phylogeny of Mesozoic mammals ZHE−XI LUO, ZOFIA KIELAN−JAWOROWSKA, and RICHARD L. CIFELLI Luo, Z.−X., Kielan−Jaworowska, Z., and Cifelli, R.L. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica 47 (1): 1–78. We propose a phylogeny of all major groups of Mesozoic mammals based on phylogenetic analyses of 46 taxa and 275 osteological and dental characters, using parsimony methods (Swofford 2000). Mammalia sensu lato (Mammaliaformes of some authors) are monophyletic. Within mammals, Sinoconodon is the most primitive taxon. Sinoconodon, morganu− codontids, docodonts, and Hadrocodium lie outside the mammalian crown group (crown therians + Monotremata) and are, successively, more closely related to the crown group. Within the mammalian crown group, we recognize a funda− mental division into australosphenidan (Gondwana) and boreosphenidan (Laurasia) clades, possibly with vicariant geo− graphic distributions during the Jurassic and Early Cretaceous. We provide additional derived characters supporting these two ancient clades, and we present two evolutionary hypotheses as to how the molars of early monotremes could have evolved. We consider two alternative placements of allotherians (haramiyids + multituberculates). The first, supported by strict consensus of most parsimonious trees, suggests that multituberculates (but not other alllotherians) are closely re− lated to a clade including spalacotheriids + crown therians (Trechnotheria as redefined herein). Alternatively, allotherians can be placed outside the mammalian crown group by a constrained search that reflects the traditional emphasis on the uniqueness of the multituberculate dentition. Given our dataset, these alternative topologies differ in tree−length by only ~0.6% of the total tree length; statistical tests show that these positions do not differ significantly from one another. -
Review of the Early Allotherian Mammals
Review of the early allotherian mammals Percy M. Butler Acta Palaeontologica Polonica 45 (4), 2000: 317-342 Comparison of the early allotherian genera, Haramiyavia, Thomasia, Theroteinus, and Eleutherodon shows that their molariform teeth are variants of a common pattern, justifying the inclusion of these genera in a single order Haramiyida. Haramiyavia is made the type of a new family Haramiyaviidae. The order Haramiyida is divided into two suborders: (1) Theroteinida (only family Theroteinidae), and (2) Haramiyoidea (families Haramiyaviidae, Haramiyidae, Eleutherodontidae). Dental resemblances support the hypothesis that the Multituberculata originated within the Haramiyida, in which case the Haramiyida would be paraphyletic. Derivation of multituberculates from within the Mammaliaformes would involve a highly improbable transformation of the dentition. It is therefore postulated that allotherian (Haramiyida + Multituberculata) and non-allotherian mammaliaform clades separated before the Mammaliaformes developed a shearing dentition with unilateral occlusion and transverse jaw movements. This hypothesis implies that the two clades evolved to a large extent in parallel, to account for the apparent synapomorphies of multituberculates and therians. Key words: Haramiyida, Multituberculata, molars, occlusion, homoplasy. Percy M. Butler [[email protected]], School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, United Kingdom. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see creativecommons.org), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Full text (2,563.2 kB) Powered by TCPDF (www.tcpdf.org). -
First Mesozoic Mammal from Chile: the Southernmost Record of a Late Cretaceous Gondwanatherian
Boletín del Museo Nacional de Historia Natural, Chile, 69 (1): 5-31 (2020) 5 FIRST MESOZOIC MAMMAL FROM CHILE: THE SOUTHERNMOST RECORD OF A LATE CRETACEOUS GONDWANATHERIAN Francisco J. Goin1, Agustín G. Martinelli2, Sergio Soto-Acuña3, Emma C. Vieytes4*, Leslie M.E. Manríquez5, Roy A. Fernández3**, Juan Pablo Pino6, Cristine Trevisan6***, Jonatan Kaluza3,7, Marcelo A. Reguero8****, Marcelo Leppe6*****, Héctor Ortiz3******, David Rubilar-Rogers9 and Alexander O. Vargas3******* 1CONICET-División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina. E-mail: [email protected] 2CONICET-Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Av. Ángel Gallardo 470, C1405DJR, CABA, Argentina. E-mail: [email protected] 3Red Paleontológica U-Chile, Laboratorio de Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de Chile. Las Palmeras 3425, Ñuñoa, Santiago, Chile. E-mail: [email protected] 4CONICET-División Zoología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, B1900FWA La Plata, Argentina. E-mail: [email protected] 5Programa de Pós-Graduação em Geologia, Universidade do Vale do Rio dos Sinos, Av. UNISINOS 950, 93022- 000 São Leopoldo, Rio Grande do Sul, Brasil. E-mail: [email protected] 6Laboratorio de Paleobiología de Antártica y Patagonia, Instituto Antártico Chileno, Plaza Muñoz Gamero, 1055, Punta Arenas, Chile. E-mail: [email protected] 7Fundación de Historia -
Review of the Early Allotherian Mammals
Review of the early allotherian mammals PERCY M. BUTLER Butler, P.M. 2000. Review of the early allotherian mammals. -Acta Palaeontologica Polonica 45,4, 317-342. Comparison of the early allotherian genera, Haramiyavia, Thomasia, Theroteinus, and Eleutherodon shows that their molarifom teeth are variants of a common pattern, justify- ing the inclusion of these genera in a single order Haramiyida. Haramiyavia is made the type of a new family Haramiyaviidae. The order Haramiyida is divided into two suborders: (1) Theroteinida (only family Theroteinidae), and (2) Haramiyoidea (families Haramiyaviidae, Haramiyidae, Eleutherodontidae). Dental resemblances support the hy- pothesis that the Multituberculata originated within the Haramiyida, in which case the Haramiyida would be paraphyletic. Derivation of multituberculates from within the Mammaliaformes would involve a highly improbable transformation of the dentition. It is therefore postulated that allotherian (Haramiyida + Multituberculata) and non-allo- therian mammaliaform clades separated before the Mammaliaformes developed a shear- ing dentition with unilateral occlusion and transverse jaw movements. This hypothesis implies that the two clades evolved to a large extent in parallel, to account for the appar- ent synapomorphies of multituberculates and therians. Key words : Haramiyida, Multituberculata, molars, occlusion, homoplasy. Percy M. Butler [percy @ butler92freesewe.co.uk], School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 OEX, United Kingdom. Introduction The term Allotheria was used originally by Marsh (1880) for an order of mammals, embracing extinct forms characterized by the possession of cheek teeth with two or more longitudinal rows of cusps. They included not only those later known as multituberculates, but also Tritylodon (now removed from the Mamrnalia) and 'Microlestes', now Thomasia.