Results 31 to 40 of about 717 (179)

New findings in a 400 million-year-old Devonian placoderm shed light on jaw structure and function in basal gnathostomes [PDF]

Scientific Reports, 2017
Arthodire placoderms have been proposed as the sister group of Chinese ‘maxillate’ placoderms plus all the more crownward gnathostomes. These basal groups provide key information for understanding the early evolution of jaws.
Yuzhi Hu, Jing Lu, Gavin C. Young
doaj   +3 more sources

Giant, swimming mouths: oral dimensions of extant sharks do not accurately predict body size in Dunkleosteus terrelli (Placodermi: Arthrodira) [PDF]

PeerJ, 2023
Background The size of Dunkleosteus and other late Devonian arthrodire placoderms has been a persistent problem in paleontology. The bony head and thoracic armor of these animals are typically the only elements preserved in the fossil record, with the ...
Russell Engelman
doaj   +3 more sources

Cautionary tales on the use of proxies to estimate body size and form of extinct animals. [PDF]

Ecol Evol
Reconstructing the body size and form of extinct animals is of vital importance to our understanding of macroevolution and palaeontology. This is often done using anatomical proxies where extinct species are known only from fragmentary remains. However, there are many limitations influencing the selection of proxy taxa that are frequently overlooked ...
Gayford JH, Engelman RK, Sternes PC, Itano WM, Bazzi M, Collareta A, Salas-Gismondi R, Shimada K.   +7 more
europepmc   +2 more sources

Histology of "placoderm" dermal skeletons: Implications for the nature of the ancestral gnathostome [PDF]

Journal of Morphology, 2013
The vertebrate dermal skeleton has long been interpreted to have evolved from a primitive condition exemplified by chondrichthyans. However, chondrichthyans and osteichthyans evolved from an ancestral gnathostome stem-lineage in which the dermal skeleton
Ruecklin, Martin, Donoghue, Philip C. J., Giles, Sam   +2 more
core   +5 more sources

A Silurian maxillate placoderm illuminates jaw evolution

Science, 2016
The discovery of Entelognathus revealed the presence of maxilla, premaxilla, and dentary, supposedly diagnostic osteichthyan bones, in a Silurian placoderm. However, the relationship between these marginal jaw bones and the gnathal plates of conventional
Liantao Jia, Ahlberg, Per E.,, Pan, Zhaohui,, Jing Lu, Jia, Liantao,, Wenjin Zhao, Zhu, Min,, Zhu, Youan,, Qiao, Tuo,, Zhaohui Pan, Min Zhu, Per E. Ahlberg, Zhao, Wenjin,, Tuo Qiao, Youan Zhu, Lu, Jing,   +15 more
core   +3 more sources

Evolution of the vertebrate neurocranium: problems of the premandibular domain and the origin of the trabecula [PDF]

Zoological Letters, 2018
The subdivision of the gnathostome neurocranium into an anterior neural crest-derived moiety and a posterior mesodermal moiety has attracted the interest of researchers for nearly two centuries.
Shigeru Kuratani, Per. E. Ahlberg
doaj   +2 more sources

Devonian antiarch placoderms from Belgium revisited [PDF]

, 2015
peer reviewedAnatomical, systematic, and paleobiogeographical data on the Devonian antiarchs from Belgium are reviewed, updated and completed thanks to new data from the field and re-examination of paleontological collections.
Olive, S., Olive, Sébastien, Sébastien Olive   +2 more
core   +3 more sources

Taxonomical and ecological characteristics of the desmids placoderms in reservoir: analyzing the spatial and temporal distribution

Acta Limnologica Brasiliensia, 2014
AIM: This study aimed to evaluate the influence of river-dam axis and abiotic factors on the composition of Closteriaceae, Gonatozygaceae, Mesotaeniaceae and Peniaceae in a tropical reservoir METHODS: Water samples for physical, chemical and periphyton ...
Liliana Rodrigues, Sirlene Aparecida Felisberto   +1 more
exaly   +3 more sources

Bony-fish-like scales in a Silurian maxillate placoderm. [PDF]

Nat Commun, 2023
AbstractMajor groups of jawed vertebrates exhibit contrasting conditions of dermal plates and scales. But the transition between these conditions remains unclear due to rare information on taxa occupying key phylogenetic positions. The 425-million-year-old fishEntelognathuscombines an unusual mosaic of characters typically associated with jawed stem ...
Cui X, Friedman M, Yu Y, Zhu YA, Zhu M.
europepmc   +4 more sources

Placoderm muscles and chordate interrelationships [PDF]

Biology Letters, 2007
[Trinajstic et al. (2007)][1] reported exceptionally preserved soft tissues in two placoderm fish from the Devonian of Australia. This exciting finding presents fresh morphological data with a bearing on an old phylogenetic problem: deep branching structure within the vertebrate tree.
Friedman, M, Brazeau, M, Brazeau, M
openaire   +3 more sources