학술논문
Extreme lower jaw elongation in a placoderm reflects high disparity and modularity in early vertebrate evolution.
Document Type
Academic Journal
Author
Jobbins M; Department of Palaeontology, University of Zurich, Karl-Schmid-Strasse 4, 8004 Zurich, Switzerland.; Rücklin M; Naturalis Biodiversity Center, Darwinweg 2, 2333 Leiden, The Netherlands.; University of Leiden, Sylviusweg 72, 2333 Leiden, The Netherlands.; Sánchez Villagra MR; Department of Palaeontology, University of Zurich, Karl-Schmid-Strasse 4, 8004 Zurich, Switzerland.; Lelièvre H; 101 Muséum National d'Histoire Naturelle, 57 rue Cuvier, 75005 Paris, France.; Grogan E; Department of Biology, Saint Joseph's University, 5600 City Avenue, 19131 Pennsylvania, PA, USA.; Szrek P; Polish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warsaw, Poland.; Klug C; Department of Palaeontology, University of Zurich, Karl-Schmid-Strasse 4, 8004 Zurich, Switzerland.
Source
Publisher: Royal Society Publishing Country of Publication: England NLM ID: 101647528 Publication Model: eCollection Cited Medium: Print ISSN: 2054-5703 (Print) Linking ISSN: 20545703 NLM ISO Abbreviation: R Soc Open Sci Subsets: PubMed not MEDLINE
Subject
Language
English
ISSN
2054-5703
Abstract
Jaws 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. Modularity can be expressed through disproportional lengths of lower and upper jaws as in swordfish or halfbeaks. Alienacanthus malkowskii is an arthrodire from the Famennian of Morocco and Poland, whose most remarkable feature is its lower jaw, which is twice as long as the skull. This is the oldest record of such extreme jaw elongation and modularity in vertebrates. The gnathal plates of Alienacanthus possess sharp, posteriorly recurved teeth that continue anterior of the occlusion in the inferognathals. The dentition suggests a catching and trapping live prey function, and the jaw occlusion is unique among placoderms. This armoured 'fish' expands the morphological and ecological diversity during one of the first radiations of jawed vertebrates with a combination of features so far unrecorded for arthrodires.
Competing Interests: We have no competing interests.
(© 2024 The Authors.)
Competing Interests: We have no competing interests.
(© 2024 The Authors.)