Results 21 to 30 of about 696 (179)
Reappraisal of the Silurian placoderm Silurolepis and insights into the dermal neck joint evolution [PDF]
Royal Society Open Science, 2019 Silurolepis platydorsalis, a Silurian jawed vertebrate originally identified as an antiarch, is here redescribed as a maxillate placoderm close to Qilinyu and is anteroposteriorly reversed as opposed to the original description.
You-an Zhu, Jing Lu, Min Zhu
doaj +2 more sources
The relationships of antiarchs (Devonian placoderm fishes)—evidence supporting placoderm monophyly
Journal of Vertebrate Paleontology, 2008 A recent analysis of the vascularization of the pectoral fin in antiarchs indicated that they resembled jawless osteostracans rather than other jawed vertebrates, thereby challenging the monophyly of the class Placodermi. Examination of the evidence proposed to support this new hypothesis shows misinterpretation of well-established morphology in a ...
Gavin C. Young
exaly +2 more sources
New placoderm fishes from the Late Devonian of South Africa
Journal of Vertebrate Paleontology, 1997 New placoderm fishes are described from a black shale lens in the Famennian Witpoort Formation, near Grahamstown, South Africa. Arthrodires include a new species of Groenlandaspis, G. riniensis sp.
John A. Long
exaly +2 more sources
The Late Devonian placoderm Aspidichthys Newberry, 1873 from the Holy Cross Mountains, Poland [PDF]
Fossil Record, 2016 The reported placoderm remains from the Holy Cross Mountains, Poland, belong to the species Aspidichthys ingens Koenen, 1883. This study focuses on the material described in the past from Wietrznia Quarry but the new specimens were also collected form ...
P. G. Dworczak, P. Szrek
doaj +2 more sources
A Silurian placoderm with osteichthyan-like marginal jaw bones
Nature, 2013 The gnathostome (jawed vertebrate) crown group comprises two extant clades with contrasting character complements. Notably, Chondrichthyes (cartilaginous fish) lack the large dermal bones that characterize Osteichthyes (bony fish and tetrapods). The polarities of these differences, and the morphology of the last common ancestor of crown gnathostomes ...
Zhu, Min +10 more
openaire +3 more sources
An examination of the Devonian fishes of Michigan [PDF]
PeerJ, 2018 We surveyed the taxa, ecosystems, and localities of the Devonian fishes of Michigan to provide a framework for renewed study, to learn about the diversity and number of these fishes, and to investigate their connection to other North American faunas ...
Jack Stack, Lauren Sallan
doaj +3 more sources
<i>Vampyrella crystallifera</i> sp. nov., an Amoeba That Dissolves Entire Algal Cells at a Remarkable Speed. [PDF]
Ecol EvolThe new vampyrellid amoeba Vampyrella crystallifera inhabits wet Sphagnum plants in temperate moorlands. Unlike its congeners, it engulfs entire algal cells and breaks them down at a fascinating speed. This represents a feeding habit that was unexpected for the genus Vampyrella and showcases the exceptional diversity of predator–prey interactions found
Suthaus A, Hess S.
europepmc +2 more sources
Paleo-evo-devo implications of a revised conceptualization of enameloids and enamels. [PDF]
Biol Rev Camb Philos SocABSTRACT Understanding the origin and evolution of the mineralized skeleton is crucial for unravelling vertebrate history. However, several limitations hamper our progress. The first obstacle is the lack of uniformity and clarity in the literature for the definition of the tissues of concern, especially of enameloid(s) and enamel(s), resulting in ...
Houée G +3 more
europepmc +2 more sources
Cautionary tales on the use of proxies to estimate body size and form of extinct animals. [PDF]
Ecol EvolReconstructing 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 +7 more
europepmc +2 more sources
Histology of “placoderm” dermal skeletons: Implications for the nature of the ancestral gnathostome [PDF]
Journal of Morphology, 2013 AbstractThe 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 was more extensively developed.
Sam Giles +2 more
exaly +5 more sources