Results 21 to 30 of about 717 (179)

A large Middle Devonian eubrachythoracid ‘placoderm’ (Arthrodira) jaw from northern Gondwana [PDF]

Swiss Journal of Palaeontology, 2021
For the understanding of the evolution of jawed vertebrates and jaws and teeth, ‘placoderms’ are crucial as they exhibit an impressive morphological disparity associated with the early stages of this process.
Melina Jobbins, Martin Rücklin, Thodoris Argyriou, Christian Klug   +3 more
doaj   +2 more sources

Copulation in antiarch placoderms and the origin of gnathostome internal fertilisation [PDF]

Nature, 2014
Reproduction in jawed vertebrates (gnathostomes) involves either external or internal fertilization. It is commonly argued that internal fertilization can evolve from external, but not the reverse.
Trinajstic, K., Lee, Michael S.Y.,, Brian Choo, Kate Trinajstic, Johanson, Z., den Blaauwen, J., Long, John A, Zhu Min, Long, J., Ahlberg, P., Blaauwen, J., Michael Newman, Long, John A., John A. Long, Zerina Johanson, Ahlberg, Per, den Blaauwen, Jan L, Mark-Kurik, Elga,, Johanson, Zerina,, Young, Gavin C.,, Young, G., Choo, Brian, Trinajstic, Katherine, Young, Gavin, Min, Z., Gavin C. Young, Young, Gavin C., den Blaauwen, Jan,, Lee, M., Trinajstic, Kate, Trinajstic, Kate,, Jones, R., Young, Gavin C, Michael S. Y. Lee, Lee, Michael S. Y., Ahlberg, Per E, Choo, B., Per E. Ahlberg, Lee, Michael S Y, Min, Zhu, Johanson, Zerina, Mark-Kurik, Elga, Blaauwen, Jan den, Choo, Brian,, Long, John, Ahlberg, Per Erik,, Jan den Blaauwen, Zhu, Min,, Newman, Michael, Ahlberg, Per E., den Blaauwen, Jan, Roger Jones, Mark-Kurik, E., Jones, Roger, Newman, M., Elga Mark-Kurik, Long, John A.,   +56 more
core   +6 more sources

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

Oligodendrogenesis in Evolution, Development and Adulthood. [PDF]

Glia
Main Points Oligodendrocytes and myelin took shape in jawed vertebrates During development, OPCs are originated from NSCs and then undergo differentiation into mature oligodendrocytes that supply myelin. OPCs persist in the adult CNS and continue to produce oligodendrocytes and myelin.
Hu H, Gao T, Zhao J, Li H.
europepmc   +2 more sources

Functional anatomy, jaw mechanisms, and feeding behavior of Dunkleosteus terrelli (Placodermi, Arthrodira). [PDF]

Anat Rec (Hoboken)
A new musculoskeletal reconstruction and revision of the cranio‐mandibular anatomy of the Devonian arthrodire placoderm Dunkleosteus terrelli from a comparative and functional anatomical perspective. Dunkleosteus is a specialized arthrodire with many specializations for feeding on large vertebrates, and many of its features are part of broader ...
Engelman RK, Carr RK, Trinajstic K, Johanson Z, Lebedev OA.   +4 more
europepmc   +2 more sources

Placoderms and the evolutionary origin of teeth: a comment on Rucklin & Donoghue (2015) [PDF]

Biology Letters, 2019
The extinct Devonian placoderms (armoured jawed fishes) [1,2] are central to the question of tooth origins, because some have denticulate ‘toothplates’ within the mouth cavity. A key question is whether these gnathal plates were modified from external
Young, Gavin, Burrow, Carole J., Hu, Yuzhi   +2 more
core   +5 more sources

A new ‘acanthothoracid’ placoderm from the Arctic Canada (Early Devonian) and its bearing on the evolution of jaws and teeth [PDF]

Royal Society Open Science
The origin of jaws and teeth represents one of the most formative episodes in our own evolutionary history. However, this event is poorly understood because of a lack of detailed knowledge of key lineages, including the ‘acanthothoracid’ placoderms ...
Sébastien Olive, Ilias Kotoulas, Daniel Goujet, Philip C. J. Donoghue, Federica Marone, Martin Rücklin   +5 more
doaj   +2 more sources

Placoderms from the Lower Devonian “placoderm sandstone” of the Holy Cross Mountains, Poland with biostratigraphical and palaeobiogeographical implications [PDF]

Acta Palaeontologica Polonica, 2017
The siliciclastic sequence of the Lower Devonian of the southern part of the Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains. Study of the
Piotr Szrek, Vincent Dupret
doaj   +5 more sources

Investigating the Morphogenesis and Replacement of Lamprey Toothlets Using Synchrotron Imaging. [PDF]

J Morphol
Toothlet replacement is a conserved feature in lampreys. We describe the mechanism at tissue level and quantify the determining factors, thus providing the basis for studies into a deep homology of cyclostome toothlets and gnathostome teeth. ABSTRACT Teeth are a key innovation that underpinned the adaptive radiation of jawed vertebrates; however, their
Grohganz M, Leyhr J, Johanson Z, Haitina T, Sanchez S, Dollman K, Stundl J, Bronner ME, Fraser GJ, Donoghue PCJ.   +9 more
europepmc   +2 more sources

Confocal Characterization of Intestinal Dendritic Cells from Myxines to Teleosts [PDF]

Biology, 2022
Dendritic cells (DCs) are antigen-presenting cells (APCs) that regulate the beginning of adaptive immune responses. The mechanisms of tolerance to antigens moving through the digestive tract are known to be regulated by intestinal DCs.
Alessio Alesci, Gioele Capillo, Angelo Fumia, Emmanuele Messina, Marco Albano, Marialuisa Aragona, Patrizia Lo Cascio, Nunziacarla Spanò, Simona Pergolizzi, Eugenia Rita Lauriano   +9 more
doaj   +2 more sources