New Data on the Paleocene Monotreme Monotrematum Sudamericanum, and the Convergent Evolution of Triangulate Molars
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Miocene Mammal Reveals a Mesozoic Ghost Lineage on Insular New Zealand, Southwest Pacific
Miocene mammal reveals a Mesozoic ghost lineage on insular New Zealand, southwest Pacific Trevor H. Worthy*†, Alan J. D. Tennyson‡, Michael Archer§, Anne M. Musser¶, Suzanne J. Hand§, Craig Jonesʈ, Barry J. Douglas**, James A. McNamara††, and Robin M. D. Beck§ *School of Earth and Environmental Sciences, Darling Building DP 418, Adelaide University, North Terrace, Adelaide 5005, South Australia, Australia; ‡Museum of New Zealand Te Papa Tongarewa, P.O. Box 467, Wellington 6015, New Zealand; §School of Biological, Earth and Environmental Sciences, University of New South Wales, New South Wales 2052, Australia; ¶Australian Museum, 6-8 College Street, Sydney, New South Wales 2010, Australia; ʈInstitute of Geological and Nuclear Sciences, P.O. Box 30368, Lower Hutt 5040, New Zealand; **Douglas Geological Consultants, 14 Jubilee Street, Dunedin 9011, New Zealand; and ††South Australian Museum, Adelaide, South Australia 5000, Australia Edited by James P. Kennett, University of California, Santa Barbara, CA, and approved October 11, 2006 (sent for review July 8, 2006) New Zealand (NZ) has long been upheld as the archetypical Ma) dinosaur material (13) and isolated moa bones from marine example of a land where the biota evolved without nonvolant sediments up to 2.5 Ma (1, 14), the terrestrial record older than terrestrial mammals. Their absence before human arrival is mys- 1 Ma is extremely limited. Until now, there has been no direct terious, because NZ was still attached to East Antarctica in the Early evidence for the pre-Pleistocene presence in NZ of any of its Cretaceous when a variety of terrestrial mammals occupied the endemic vertebrate lineages, particularly any group of terrestrial adjacent Australian portion of Gondwana. -
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nicolás r chimento, Federico L agnolin y Fernando e novas Museo Argentino de Ciencias Naturales Bernardino Rivadavia Necrolestes un mamífero patagónico que sobrevivió a la extinción de los dinosaurios Un descubrimiento patagónico desembocadura del río Santa Cruz, descubrieron esque- letos fósiles prácticamente completos del Necrolestes. El es- En 1891, Florentino Ameghino (1854-1911) dio a tudio de esos esqueletos llevó a pensar que se trataba de conocer unos restos fósiles encontrados por su hermano un mamífero muy arcaico en la historia de la evolución, Carlos (1865-1936) en las barrancas de Monte Obser- más que un ancestro de los topos, como había supuesto vación, en la provincia de Santa Cruz, en yacimientos Ameghino. Por determinados rasgos se pensó que podía de unos 17 millones de años de antigüedad. Determinó haber sido un marsupial, es decir, un pariente lejano de las que pertenecían a un pequeño –escasos 10cm de largo, comadrejas, los canguros y los coalas actuales. del hocico a la cola– y desconocido mamífero extin- Ciertos investigadores aceptaron esta última hipótesis guido. Estudió los diminutos huesos y consideró que de parentesco, pero otros se mostraron escépticos acerca el animal habría sido un pariente lejano de los topos de ella y se inclinaron por considerar inciertas las rela- africanos vivientes. Le dio el nombre científicoN ecrolestes ciones genealógicas del diminuto mamífero. Así, su po- patagonensis, es decir, ladrón de tumbas de la Patagonia, en sición en el árbol evolutivo de los mamíferos fue objeto alusión a sus hábitos excavadores. El hallazgo, publica- de debate durante gran parte del siglo XX. Para algunos, do por Ameghino en el número de la Revista Argentina de era pariente lejano de las mulitas; otros seguían pensan- Historia Natural citado entre las lecturas sugeridas, atrajo do que podía estar relacionado con los topos, y para un la atención del ámbito científico, ya que hasta ese mo- tercer grupo, sus vínculos eran con los marsupiales aus- mento en Sudamérica no se habían encontrado restos tralianos. -
0 Introduction
Cambridge University Press 978-0-521-78117-6 - Evolution of Tertiary Mammals of North America, Volume 2: Small Mammals, Xenarthrans, and Marine Mammals Christine M. Janis, Gregg F. Gunnell and Mark D. Uhen Excerpt More information 0 Introduction christine m. janis,1 gregg f. gunnell2 and mark d. uhen3 1Brown University, Providence, RI, USA 2Museum of Paleontology, University of Michigan, Ann Arbor, MI, USA 3Smithsonian Institution, Washington, DC, USA AIMS OF VOLUME 2 the chapter are presented according to a standardized format, and the institutional abbreviations have also been standardized and are This enterprise was originally conceived of as a single volume. How- listed in an appendix (Appendix III). ever, after a span of 10 years from its original conception, the current senior editor (Christine Janis), and the then junior editors (Kathleen Scott and Louis Jacobs) realized that it would be more realistic THE STANDARDIZED LAYOUT OF EACH CHAPTER to proceed with chapters then in hand, which could more or less be assembled into the conceptually useful, if taxonomically para- The chapters are laid out in a similar fashion to those in Volume 1. phyletic, rubric of “Terrestrial Carnivores and Ungulates” (Janis, The contributors were requested to adhere to a common layout for Scott, and Jacobs, 1998). This in part reflected the chapters that had each chapter, in order to provide uniform information throughout been assembled to date, although it should be noted that some of the book. The “Introduction” for each chapter introduces the group. the chapters in this current volume, most notably those by Darryl The “Defining features” section lays out the basic cranial, dental, Domning on sirenians and desmostylians, were among the first ones and postcranial features of the taxon. -
Like Globin Genes in Monotremes and Therian Mammals
Genomic evidence for independent origins of -like globin genes in monotremes and therian mammals Juan C. Opazo*, Federico G. Hoffmann, and Jay F. Storz† School of Biological Sciences, University of Nebraska, Lincoln, NE 68588 Edited by Morris Goodman, Wayne State University School of Medicine, Detroit, MI, and approved December 13, 2007 (received for review November 5, 2007) Phylogenetic reconstructions of the -globin gene family in ver- embryonic -globin gene is exclusively expressed in primitive tebrates have revealed that developmentally regulated systems of erythroid cells derived from the yolk sac. However, the ‘‘- hemoglobin synthesis have been reinvented multiple times in globin’’ gene in birds is not orthologous to the -globin gene in independent lineages. For example, the functional differentiation mammals (2, 12), because they are independently derived from of embryonic and adult -like globin genes occurred independently lineage-specific duplications of a proto -globin gene. in birds and mammals. In both taxa, the embryonic -globin gene In placental mammals (subclass Eutheria), the -globin gene is exclusively expressed in primitive erythroid cells derived from cluster includes a linked set of three early expressed (prenatal) the yolk sac. However, the ‘‘-globin’’ gene in birds is not ortholo- genes, -␥-,atthe5Ј end of the cluster, and a pair of late gous to the -globin gene in mammals, because they are indepen- expressed (adult) genes, ␦ and ,atthe3Ј end. There is extensive dently derived from lineage-specific duplications of a proto variation in the copy number of these different paralogs among -globin gene. Here, we report evidence that the early and late species, and in a number of placental mammal lineages, the - expressed -like globin genes in monotremes and therian mam- and ␦-globin genes have been inactivated or deleted (13–15). -
The Oldest Platypus and Its Bearing on Divergence Timing of the Platypus and Echidna Clades
The oldest platypus and its bearing on divergence timing of the platypus and echidna clades Timothy Rowe*†, Thomas H. Rich‡§, Patricia Vickers-Rich§, Mark Springer¶, and Michael O. Woodburneʈ *Jackson School of Geosciences, University of Texas, C1100, Austin, TX 78712; ‡Museum Victoria, PO Box 666, Melbourne, Victoria 3001, Australia; §School of Geosciences, PO Box 28E, Monash University, Victoria 3800, Australia; ¶Department of Biology, University of California, Riverside, CA 92521; and ʈDepartment of Geology, Museum of Northern Arizona, Flagstaff, AZ 86001 Edited by David B. Wake, University of California, Berkeley, CA, and approved October 31, 2007 (received for review July 7, 2007) Monotremes have left a poor fossil record, and paleontology has broadly affect our understanding of early mammalian history, been virtually mute during two decades of discussion about with special implications for molecular clock estimates of basal molecular clock estimates of the timing of divergence between the divergence times. platypus and echidna clades. We describe evidence from high- Monotremata today comprises five species that form two resolution x-ray computed tomography indicating that Teinolo- distinct clades (16). The echidna clade includes one short-beaked phos, an Early Cretaceous fossil from Australia’s Flat Rocks locality species (Tachyglossus aculeatus; Australia and surrounding is- (121–112.5 Ma), lies within the crown clade Monotremata, as a lands) and three long-beaked species (Zaglossus bruijni, Z. basal platypus. Strict molecular clock estimates of the divergence bartoni, and Z. attenboroughi, all from New Guinea). The between platypus and echidnas range from 17 to 80 Ma, but platypus clade includes only Ornithorhynchus anatinus (Austra- Teinolophos suggests that the two monotreme clades were al- lia, Tasmania). -
Fossil Focus: Dinosaurs Down Under Author(S): Stephen F
www.palaeontologyonline.com |Page 1 Title: Fossil Focus: Dinosaurs Down Under Author(s): Stephen F. Propat *1 Volume: 5 Article: 1 Page(s): 1-11 Published Date: 01/01/2015 PermaLink: http://www.palaeontologyonline.com/articles/2015/fossil-focus-dinosaurs/ IMPORTANT Your use of the Palaeontology [online] archive indicates your acceptance of Palaeontology [online]'s Terms and Conditions of Use, available at http://www.palaeontologyonline.com/site-information/terms-and-conditions/. COPYRIGHT Palaeontology [online] (www.palaeontologyonline.com) publishes all work, unless otherwise stated, under the Creative Commons Attribution 3.0 Unported (CC BY 3.0) license. This license lets others distribute, remix, tweak, and build upon the published work, even commercially, as long as they credit Palaeontology[online] for the original creation. This is the most accommodating of licenses offered by Creative Commons and is recommended for maximum dissemination of published material. Further details are available at http://www.palaeontologyonline.com/site-information/copyright/. CITATION OF ARTICLE Please cite the following published work as: Propat, Stephen F.. 2015. Fossil Focus: Dinosaurs Down Under, Palaeontology Online, Volume 5, Article 1, 1- 11. Published by: Palaeontology [online] www.palaeontologyonline.com |Page 2 Fossil Focus: Dinosaurs Down Under by Stephen F. Poropat*1,2 Introduction: Ask the average person in the street to name an Australian dinosaur, and you will be lucky if you get a correct answer. If they say crocodile, they are in the right postcode but have the wrong address. If they say emu, then they are correct, strictly speaking, but they are either lucky or being smart. If they say kangaroo, back away slowly and avoid eye contact. -
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. -
Mesozoic: the Dark Age for Mammals!
Ed’s Simplified History of the Mammals Note progression from Pelycosaurs (1) to Therapsids and Cynodonts (2) in Triassic. Stem mammals appeared in Late Triassic and Early Jurassic (3). Relationships among the Middle Jurassic forms (4) are controversial (see handout). Therian clade, identified by the tribosphenic molar (5), emerged at the end of the Jurassic, Early Cretaceous. A slightly more detailed version… in case you like something that looks more slick From Pough et al. 2009. Vertebrate Life, 8th ed. Pelycosaurs Dominated the late Permian, gave rise to therapsids Therapsids Rapid radiation in late Permian, around 270 MYA Still “mammal-like reptiles” The mass extinction at the end of the Permian was the greatest loss of diversity ever with >80% of all known genera and about 90% of all species going extinct, both terrestrial and marine. Cynodonts Late Permian to mid Triassic Last remaining group of therapsids, survived mass extinction at the end of the Permian. Persisted well Only 1 lineage of into Triassic and developed cynodonts survived many features associated through the late Triassic, with mammals. and this group became ancestors of mammals. Mesozoic: the Dark Age for Mammals! multituberculate Morganucodon, one of the earliest mammals (What else was happening in the Late Triassic and Jurassic Hadrocodium that may have contributed to mammals becoming small and Most were very small with nocturnal?) conservative morphology ...but new fossil finds indicate more diversity than we thought Repenomanus Still, largest known mammal during Mesozic Most were shrew to is no larger than a mouse sized, for 125 woodchuck million years! Some Mesozoic events and mammals you should know 1. -
Eutheria (Placental Mammals)
Eutheria (Placental Introductory article Mammals) Article Contents . Introduction J David Archibald, San Diego State University, San Diego, California, USA . Basic Design . Taxonomic and Ecological Diversity Eutheria includes one of three major clades of mammals, the extant members of which are . Fossil History and Distribution referred to as placentals. Phylogeny Introduction have supernumerary teeth (e.g. some whales, armadillos, Eutheria (or Placentalia) is the most taxonomically diverse etc.), in extant placentals the number of teeth is at most of three branches or clades of mammals, the other two three upper and lower incisors, one upper and lower being Metatheria (or Marsupialia) and Prototheria (or canine, four upper and lower premolars, and three upper Monotremata). When named by Gill in 1872, Eutheria and lower molars. Except for one fewer upper molar, a included both marsupials and placentals. It was Huxley in domestic dog retains this pattern. Compared to reptiles, 1880 that recognized Eutheria basically as used today to mammals have fewer skull bones through fusion and loss, include only placentals. McKenna and Bell in their although bones are variously emphasized in each of the Classification of Mammals, published in 1997, chose to three major mammalian taxa. use Placentalia rather than Eutheria to avoid the confusion Physiologically, mammals are all endotherms of varying of what taxa should be included in Eutheria. Others such as degrees of efficiency. They are also homeothermic with a Rougier have used Eutheria and Placentalia in the sense relatively high resting temperature. These characteristics used here. Placentalia includes all extant placentals and are also found in birds, but because of anatomical their most recent common ancestor. -
SUPPLEMENTARY INFORMATION: Tables, Figures and References
Samuels et al. Evolution of the patellar sesamoid bone in mammals SUPPLEMENTARY INFORMATION: Tables, Figures and References Supplementary Table S1: Mammals$ Higher taxa Genus sp. Estimated. age of Patellar Comments# (partial) specimen, location state 0/1/2 (absent/ ‘patelloid’/ present) Sinoconodonta Sinoconodon Jurassic 0 Patellar groove absent, suggests no rigneyi (Kielan- patella Jaworowska, Cifelli & Luo, Sinoconodon is included on our 2004) phylogeny within tritylodontids. Morganucodonta Megazostrodon Late Triassic, southern 0 rudnerae (Jenkins Africa & Parrington, 1976) Morganucodonta Eozostrodon sp. Late Triassic, Wales 0 Asymmetric patellar groove, (Jenkins et al., specimens disarticulated so it is hard 1976) to assess the patella but appears absent Docodonta Castorocauda 164 Mya, mid-Jurassic, 0 Semi-aquatic adaptations lutrasimilis (Ji, China Luo, Yuan et al., 2006) Docodonta Agilodocodon 164 Mya, mid-Jurassic, 0 scansorius China (Meng, Ji, Zhang et al., 2015) Docodonta Docofossor 160 Mya 0 brachydactylus (Luo, Meng, Ji et al., 2015) Docodonta Haldanodon 150-155 Mya, Late 0 Shallow patellar groove exspectatus Jurassic, Portugal (Martin, 2005b) Australosphenida Asfaltomylos Mid-Jurassic, South ? Postcranial material absent patagonicus America (Martin, 2005a) Australosphenida Ornithorhynchus Extant 2 Platypus, genome sequenced Monotremata anatinus (Warren, Hillier, Marshall Graves et (Herzmark, 1938; al., 2008) Rowe, 1988) Samuels et al. Australosphenida Tachyglossus + Extant 2 Echidnas Monotremata Zaglossus spp. (Herzmark, 1938; Rowe, 1988) Mammaliaformes Fruitafossor 150 Mya, Late Jurassic, 0 Phylogenetic status uncertain indet. windscheffeli (Luo Colorado & Wible, 2005) Mammaliaformes Volaticotherium Late Jurassic/Early ? Hindlimb material incomplete indet. antiquus (Meng, Cretaceous Hu, Wang et al., 2006) Eutriconodonta Jeholodens 120-125 Mya, Early 0 Poorly developed patellar groove jenkinsi (Ji, Luo Cretaceous, China & Ji, 1999) Eutriconodonta Gobiconodon spp.