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A new species of dercetid and the assessment of the phylogeny of the Enchodontoidei (Teleostei: Aulopiformes)
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- Author / Creator
- Chida, Mori
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The Enchodontoidei is an extinct suborder of a marine teleost order Aulopiformes. Most enchodontoids have been reported from deposits of the Late Cretaceous. One of the major groups in Enchodontoidei is the family Dercetidae, which is traditionally characterized by an elongate body, long snout, triradiate dermal scutes, and reduced neural spines. Despite the long history of the taxonomic studies since the early 19th century, the phylogenetic study of enchodontoids including dercetids has been performed only relatively recently. The Enchodontoidei was recovered as a paraphyletic group in previous studies, and the family Dercetidae was supported by a single synapomorphy, neural spines very reduced. The two newly discovered specimens from southern Alberta are here assigned to a new species of the genus Dercetis, which were mainly reported from Europe and the Middle East in previous studies. The new species is recovered as a sister to the other species of Dercetis, but the family Dercetidae is not supported as a monophyletic taxon. The preexisting character matrix is modified based on the assessment of 87 characters, and the analysis with a modified character matrix recovered a monophyletic Enchodontoidei supported by a single unambiguous synapomorphy, maxilla included in gape. Overall, the description of the new specimens provides new insights into the genus Dercetis, and the assessment of the preexisting characters suggests the urgent need for additional modifications of the matrix and revision of the character coding in some taxa.
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- Subjects / Keywords
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- Graduation date
- Fall 2022
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.