Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii)
Gill skeletons provide a rich source of character information for inferring the relationships among extant fishes. However, the difficulties in accessing branchial structures in fossils have limited the use of gill-arch anatomy in phylogenetic studies of extinct fishes. Here we apply micro comput...
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| Format: | Journal article |
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Taylor and Francis
2017
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| _version_ | 1797079384618696704 |
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| author | Beckett, H Giles, S Friedman, M |
| author_facet | Beckett, H Giles, S Friedman, M |
| author_sort | Beckett, H |
| collection | OXFORD |
| description | Gill skeletons provide a rich source of character information for inferring the relationships among extant fishes. However, the difficulties in accessing branchial structures in fossils have limited the use of gill-arch anatomy in phylogenetic studies of extinct fishes. Here we apply micro computed tomography (µCT) to visualize and describe gill-arch anatomy in three-dimensionally preserved Late Cretaceous-early Paleogene remains of seven genera attributed to the eurypterygian clade Aulopiformes (lizardfishes), a group for which detailed cladistic character sets describing patterns of variation in the branchial skeleton are available. We evaluate the placement of these fossil taxa based on characters of the gill skeleton in isolation. Our results support an alepisauroid placement for †Apateodus corneti, †Cimolichthys lewesiensis and †Halec eupterygius, and a stem synodontid affinity for †Argillichthys toombsi and †Labrophagus esocinus. These placements are broadly consistent with past hypotheses based either on formal cladistic argumentation or qualitative morphological comparison drawing on other skeletal systems. We find insufficient evidence in the branchial skeleton to place †Aulopopsis depressifrons more specifically than Aulopiformes incertae sedis. Gill-arch anatomy substantially revises past interpretations of †Sardinioides illustrans by providing clear evidence for placement within Aulopiformes generally, and as either a stem aulopid or stem paralopid more specifically. This species must therefore be removed from †Sardinioides, the type of which is a myctophiform and shows conspicuous anatomical differences with †‘S.’ illustrans. Our work provides proof-of-concept for the recovery of detailed information on gill skeleton anatomy in fossils, indicating the potential for the extraction of considerable new morphological data—and phylogenetic information—from suitably preserved fossil specimens. |
| first_indexed | 2024-03-07T00:45:07Z |
| format | Journal article |
| id | oxford-uuid:845fc46d-63e3-4244-b38e-c54628e00e61 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T00:45:07Z |
| publishDate | 2017 |
| publisher | Taylor and Francis |
| record_format | dspace |
| spelling | oxford-uuid:845fc46d-63e3-4244-b38e-c54628e00e612022-03-26T21:50:39ZComparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii)Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:845fc46d-63e3-4244-b38e-c54628e00e61Symplectic Elements at OxfordTaylor and Francis2017Beckett, HGiles, SFriedman, MGill skeletons provide a rich source of character information for inferring the relationships among extant fishes. However, the difficulties in accessing branchial structures in fossils have limited the use of gill-arch anatomy in phylogenetic studies of extinct fishes. Here we apply micro computed tomography (µCT) to visualize and describe gill-arch anatomy in three-dimensionally preserved Late Cretaceous-early Paleogene remains of seven genera attributed to the eurypterygian clade Aulopiformes (lizardfishes), a group for which detailed cladistic character sets describing patterns of variation in the branchial skeleton are available. We evaluate the placement of these fossil taxa based on characters of the gill skeleton in isolation. Our results support an alepisauroid placement for †Apateodus corneti, †Cimolichthys lewesiensis and †Halec eupterygius, and a stem synodontid affinity for †Argillichthys toombsi and †Labrophagus esocinus. These placements are broadly consistent with past hypotheses based either on formal cladistic argumentation or qualitative morphological comparison drawing on other skeletal systems. We find insufficient evidence in the branchial skeleton to place †Aulopopsis depressifrons more specifically than Aulopiformes incertae sedis. Gill-arch anatomy substantially revises past interpretations of †Sardinioides illustrans by providing clear evidence for placement within Aulopiformes generally, and as either a stem aulopid or stem paralopid more specifically. This species must therefore be removed from †Sardinioides, the type of which is a myctophiform and shows conspicuous anatomical differences with †‘S.’ illustrans. Our work provides proof-of-concept for the recovery of detailed information on gill skeleton anatomy in fossils, indicating the potential for the extraction of considerable new morphological data—and phylogenetic information—from suitably preserved fossil specimens. |
| spellingShingle | Beckett, H Giles, S Friedman, M Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title | Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title_full | Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title_fullStr | Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title_full_unstemmed | Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title_short | Comparative anatomy of the gill skeleton of fossil Aulopiformes (Teleostei: Eurypterygii) |
| title_sort | comparative anatomy of the gill skeleton of fossil aulopiformes teleostei eurypterygii |
| work_keys_str_mv | AT becketth comparativeanatomyofthegillskeletonoffossilaulopiformesteleosteieurypterygii AT giless comparativeanatomyofthegillskeletonoffossilaulopiformesteleosteieurypterygii AT friedmanm comparativeanatomyofthegillskeletonoffossilaulopiformesteleosteieurypterygii |