A well-preserved ‘placoderm’ (stem-group Gnathostomata) upper jaw from the Early Devonian of Mongolia clarifies jaw evolution [PDF]
Royal Society Open Science, 2023 The origin of jaws and teeth remains contentious in vertebrate evolution. ‘Placoderms’ (Silurian-Devonian armoured jawed fishes) are central to debates on the origins of these anatomical structures.
Martin D. Brazeau +7 more
doaj +5 more sources
New information on Brindabellaspis stensioi Young, 1980, highlights morphological disparity in Early Devonian placoderms [PDF]
Royal Society Open Science, 2018 Acid-prepared specimens of the placoderm Brindabellaspis stensioi (Early Devonian of New South Wales, Australia) revealed placoderm endocranial anatomy in unprecedented detail.
Benedict King +2 more
doaj +3 more sources
Extreme lower jaw elongation in a placoderm reflects high disparity and modularity in early vertebrate evolution [PDF]
Royal Society Open ScienceJaws are a key vertebrate feature that arose early in our evolution. Placoderms are among the first jawed vertebrates; their fossils yield essential knowledge about the early diversification of gnathostome feeding strategies, diets and modularity ...
Melina Jobbins +6 more
doaj +5 more sources
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 +4 more sources
A novel specimen-based mid-Paleozoic dataset of antiarch placoderms (the most basal jawed vertebrates) [PDF]
Earth System Science Data, 2023 Antiarcha data are essential to quantitative studies of basal jawed vertebrates. The absence of structured data on key groups of early vertebrates, such as Antiarcha, has lagged in understanding their diversity and distribution patterns.
Z. Pan +5 more
doaj +2 more sources
Squamation and scale morphology at the root of jawed vertebrates [PDF]
eLife, 2022 Placoderms, as the earliest branching jawed vertebrates, are crucial to understanding how the characters of crown gnathostomes comprising Chondrichthyes and Osteichthyes evolved from their stem relatives.
Yajing Wang, Min Zhu
doaj +2 more sources
Ecomorphological inferences in early vertebrates: reconstructing Dunkleosteus terrelli (Arthrodira, Placodermi) caudal fin from palaeoecological data [PDF]
PeerJ, 2017 Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well ...
Humberto G. Ferrón +2 more
doaj +6 more sources
Early Gnathostome Phylogeny Revisited: Multiple Method Consensus. [PDF]
PLoS ONE, 2016 A series of recent studies recovered consistent phylogenetic scenarios of jawed vertebrates, such as the paraphyly of placoderms with respect to crown gnathostomes, and antiarchs as the sister group of all other jawed vertebrates.
Tuo Qiao +4 more
doaj +10 more sources
A Bayesian approach to dynamic homology of morphological characters and the ancestral phenotype of jawed vertebrates [PDF]
eLife, 2020 Phylogenetic analysis of morphological data proceeds from a fixed set of primary homology statements, the character-by-taxon matrix. However, there are cases where multiple conflicting homology statements can be justified from comparative anatomy.
Benedict King, Martin Rücklin
doaj +2 more sources
Biomechanical analyses of pterygotid sea scorpion chelicerae uncover predatory specialisation within eurypterids [PDF]
PeerJ, 2022 Eurypterids (sea scorpions) are extinct aquatic chelicerates. Within this group, members of Pterygotidae represent some of the largest known marine arthropods.
Russell D. C. Bicknell +5 more
doaj +3 more sources