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Brochu CA, de Celis A, Adams AJ, Drumheller SK, Nestler JH, Benefit BR, Grossman A, Kirera F, Lehmann T, Liutkus-Pierce C, Manthi FK, McCrossin ML, McNulty KP, Nyaboke Juma R. Giant dwarf crocodiles from the Miocene of Kenya and crocodylid faunal dynamics in the late Cenozoic of East Africa. Anat Rec (Hoboken) 2022; 305:2729-2765. [PMID: 35674271 PMCID: PMC9541231 DOI: 10.1002/ar.25005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 12/03/2022]
Abstract
We describe two new osteolaemine crocodylids from the Early and early Middle Miocene of Kenya: Kinyang mabokoensis tax. nov. (Maboko, 15 Ma) and Kinyang tchernovi tax. nov. (Karungu and Loperot, 18 Ma). Additional material referable to Kinyang is known from Chianda and Moruorot. The skull was broad and dorsoventrally deep, and the genus can be diagnosed based on the combined presence of a partial overbite, a subdivided fossa for the lateral collateral ligament on the surangular, and a maxilla with no more than 13 alveoli. Phylogenetic analyses based on morphological and combined morphological and molecular data support a referral of Kinyang to Osteolaeminae, and morphological data alone put the new taxon at the base of Euthecodontini. Some Kinyang maxillae preserve blind pits on the medial caviconchal recess wall. Kinyang co‐occurs with the osteolaemine Brochuchus at some localities, and together, they reinforce the phylogenetic disparity between early Neogene osteolaemine‐dominated faunas and faunas dominated by crocodylines beginning in the Late Miocene in the Kenya Rift. The causes of this turnover remain unclear, though changes in prevailing vegetation resulting from tectonic and climatic drivers may provide a partial explanation.
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Affiliation(s)
- Christopher A Brochu
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Ane de Celis
- Grupo de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, Madrid, Spain
| | - Amanda J Adams
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, Iowa, USA.,Department of Biological Sciences, Fort Hays State University, Hays, Kansas, USA
| | - Stephanie K Drumheller
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee, USA
| | - Jennifer H Nestler
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Brenda R Benefit
- Department of Anthropology, New Mexico State University, Las Cruces, New Mexico, USA
| | - Aryeh Grossman
- Department of Anatomy, College of Graduate Studies, Midwestern University, Glendale, Arizona, USA.,Arizona College of Veterinary Medicine, Midwestern University, Glendale, Arizona, USA.,Arizona College of Osteopathic Medicine, Midwestern University, Glendale, Arizona, USA
| | - Francis Kirera
- Mercer University School of Medicine, Macon, Georgia, USA
| | - Thomas Lehmann
- Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
| | - Cynthia Liutkus-Pierce
- Department of Geological and Environmental Sciences, Appalachian State University, Boone, North Carolina, USA
| | - Fredrick K Manthi
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - Monte L McCrossin
- Department of Anthropology, New Mexico State University, Las Cruces, New Mexico, USA
| | - Kieran P McNulty
- Department of Anthropology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Rose Nyaboke Juma
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
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Holgado B. On the validity of the genus Amblydectes Hooley 1914 (Pterodactyloidea, Anhangueridae) and the presence of Tropeognathinae in the Cambridge Greensand. AN ACAD BRAS CIENC 2021; 93:e20201658. [PMID: 34877964 DOI: 10.1590/0001-3765202120201658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 09/23/2021] [Indexed: 11/22/2022] Open
Abstract
Amblydectes is a problematic genus proposed more than a century ago for several pterosaur specimens from the Cambridge Greensand. Its problematic nature is due to the fragmentary preservation of the referred specimens, limited to several rostral tips. In the present work is reassessed the validity of Amblydectes crassidens based on new anatomical comparisons and phylogenetic analysis, as well as the description of a new specimen. The results of this work confirm the validity of the species as belonging to the clade Tropeognathinae, a recently proposed group of robust anhanguerids which have only been known so far from Gondwanan landmasses. Amblydectes is proposed as a monospecific genus, whilst one the former attributed species is assigned to a new genus, Draigwenia, which is proposed as a non-anhanguerian lanceodontian taxon of uncertain placement. The presence of a tropeognathine anhanguerid in the Cambridge Greensand suggests that anhanguerid diversity was really complex both locally and globally.
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Affiliation(s)
- Borja Holgado
- Universidade Federal do Rio de Janeiro/Museu Nacional, Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Quinta da Boa Vista s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil.,Universitat Autònoma de Barcelona, Institut Català de Paleontologia Miquel Crusafont, C/ de les Columnes, E-08193 Cerdanyola del Vallès, Barcelona, Catalonia, Spain
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