Results 81 to 90 of about 1,993,058 (236)

A second species of non‐crocodyliform crocodylomorph from the Late Triassic fissure deposits of southwestern UK: Implications for locomotory ecological diversity in Saltoposuchidae

The Anatomical Record, EarlyView.
Abstract The Late Triassic–Early Jurassic fissures of the Bristol Channel area (southwest England and south Wales) are renowned for their diverse vertebrate faunas. These assemblages have yielded an array of predominantly small‐bodied forms that are crucial to our understanding of the early evolution of several major tetrapod clades.
Ewan H. Bodenham, Stephan N. F. Spiekman, Susannah C. R. Maidment, Paul Upchurch, Philip D. Mannion   +4 more
wiley   +1 more source

A Forming Method and Theoretical Verification of Curvilinear Cylindrical Gears for Adjustable Contact Area

Jixie chuandong, 2022
To improve the contact performance of curvilinear cylindrical gears，a forming method for adjusting the contact area of tooth surfaces is proposed. Firstly，a basic scheme is established for adjusting the contact area of tooth surfaces，which means the ...
Xuegang Zhang, Yongchun Xie, Pengfei Wang   +2 more
doaj  

MicroCT reinvestigation of the only articulated fossil anostomid fish reveals synonymy of Arhinolemur Ameghino, 1898 and Megaleporinus Ramirez et al., 2017

The Anatomical Record, EarlyView.
Abstract Arhinolemur scalabrinii† Ameghino, 1898 was originally described as a strepsirrhine primate (Mammalia) but has been recognized as an anostomid fish since 2012. It remains the only extinct anostomid species known from complete cranial material.
Karen M. Panzeri, Humberto L. Andrelino, Sergio Bogan, José P. O'Gorman, Federico Agnolín, Brian L. Sidlauskas, Nahuel Vega, Agustín G. Martinelli, José L. Birindelli   +8 more
wiley   +1 more source

Redescription of the Triassic cynodont Cistecynodon parvus and reassessment of its phylogeny

The Anatomical Record, EarlyView.
Abstract Cynodontia is an important subclade of Therapsida that first occurred in the late Permian. It includes extinct subclades which are the non‐mammaliaform cynodonts and Mammaliaformes, with the latter ultimately giving rise to crown mammals. The systematics of non‐mammaliaform cynodonts has been extensively studied and is relatively well‐resolved,
Erin S. Lund, Frederik P. Wolvaardt, Roger M. H. Smith, Jaganmoy Jodder, Julien Benoit   +4 more
wiley   +1 more source

Paleopathology of a putative colossosaurian caudal vertebra (Neosauropoda: Titanosauria) from the Presidente Prudente Formation, Brazil

The Anatomical Record, EarlyView.
Abstract Studies investigating paleopathologies in sauropods remain scarce despite their relative abundance in the fossil record. In this study we report new occurrence of paleopathological features, corresponding to a neoplasm found in a middle caudal vertebra (MCT.R.2120) of an advanced titanosaur from the Presidente Prudente Formation (Bauru Basin ...
Maria Luiza Peres Bertolossi, Kamila L. N. Bandeira, Roberta Veronese do Amaral, Arthur S. Brum, Rafael C. da Silva, Valéria Gallo   +5 more
wiley   +1 more source

Evolutionary radiation of large‐bodied gorgonopsians from the lower Abrahamskraal formation of South Africa

The Anatomical Record, EarlyView.
Abstract The middle Permian represents a critical interval in therapsid evolution, when gorgonopsians emerged as some of the first specialized apex predators within terrestrial ecosystems. Despite their significance, the early diversification of Gorgonopsia in Gondwana remains poorly understood due to scarcity and fragmentary material.
Zanildo Macungo, Ricardo Araújo, Bruce S. Rubidge, Michael O. Day, Kathleen N. Dollman, Julien Benoit   +5 more
wiley   +1 more source

Design of Cam Mechanism with Negative Radius Roller-Follower

MATEC Web of Conferences, 2016
Cam mechanisms with a negative radius roller-follower allow the design of simple machines capable of exerting remarkably high forces. Furthermore, the concave-convex nature of the contact surface between the cam and the follower results in a low contact ...
Hsieh Jung-Fa, Hsieh Wen-Chang
doaj   +1 more source

Clade‐wide morphological and functional variation of the sauropsid columella

The Anatomical Record, EarlyView.
Abstract The columella (=stapes) is the middle ear bone of reptiles that transmits vibrations from the environment to the inner ear. It has been shown to exhibit extensive interspecific morphological disparity in several clades; however, its morphological variation and associated functional consequences remain poorly described.
John Peacock, Serjoscha W. Evers, Tiago R. Simões, Garth M. Spellman, Daniel J. Field   +4 more
wiley   +1 more source

Postcranial anatomy and osteohistology of an early prozostrodont cynodont from the Upper Triassic of Brazil

The Anatomical Record, EarlyView.
Abstract Prozostrodon brasiliensis, a probainognathian cynodont of the clade Prozostrodontia, is recognized as a key taxon for understanding the origin of Mammaliaformes and mammals. Despite detailed investigations of its cranial anatomy, the postcranial skeleton has received comparatively less attention.
Iasmim M. Michelotti, Lívia Roese‐Miron, Brodsky Dantas Macedo Farias, Marina Bento Soares, Leonardo Kerber   +4 more
wiley   +1 more source

Description of large, well‐preserved Enchodus specimens from the Bearpaw Formation of Alberta, Canada

The Anatomical Record, EarlyView.
Abstract Fishes of the genus Enchodus were abundant and cosmopolitan in the Late Cretaceous, but are primarily known from isolated remains in Canada. Four well‐preserved fish skulls were recovered in recent years from ammolite mines sampling the Bearpaw Formation of Southern Alberta, and are here referred to Enchodus petrosus Cope, 1874.
Luke E. Nelson, Alison M. Murray, Donald B. Brinkman   +2 more
wiley   +1 more source