Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution
The genus Astrophiura, which ranks among the most extraordinary of modern brittle stars, is the type genus of the recently resurrected family Astrophiuridae within the order Ophiurida. On account of its absurdly enlarged and strongly modified lateral arm plates, Astrophiura bears a closer resemblanc...
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PeerJ Inc.
2019-11-01
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| Online Access: | https://peerj.com/articles/8008.pdf |
| _version_ | 1797417672978202624 |
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| author | Ben Thuy Andy Gale Lea Numberger-Thuy |
| author_facet | Ben Thuy Andy Gale Lea Numberger-Thuy |
| author_sort | Ben Thuy |
| collection | DOAJ |
| description | The genus Astrophiura, which ranks among the most extraordinary of modern brittle stars, is the type genus of the recently resurrected family Astrophiuridae within the order Ophiurida. On account of its absurdly enlarged and strongly modified lateral arm plates, Astrophiura bears a closer resemblance to a pentagonal starfish than to a typical ophiuroid. Although molecular evidence suggests an ancient origin of the Astrophiuridae, dating back at least to the Early Jurassic, not a single fossil astrophiurid has been reported so far. Here, we describe dissociated lateral arm plates from the Campanian of Cringleford near Norwich, UK, and the Maastrichtian of Rügen, Germany (both Upper Cretaceous) with unambiguous astrophiurid affinities and assign these to a new species, Astrophiura markbeneckei. This represents the first fossil record of the family. In addition, the Rügen material included lateral arm plates that superficially resemble those of A. markbeneckei sp. nov. but differ in having spine articulations that are typical of the ophionereidoid family Amphilimnidae. We assign these plates to a new genus and species, Astrosombra rammsteinensis, an extinct amphilimnid with morphological modifications similar to those of Astrophiura, and thus representing a remarkable case of parallel evolution amongst brittle stars looking like starfish. |
| first_indexed | 2024-03-09T06:22:02Z |
| format | Article |
| id | doaj.art-9ce2de774a924da6947a6c4d0db51417 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:22:02Z |
| publishDate | 2019-11-01 |
| publisher | PeerJ Inc. |
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| spelling | doaj.art-9ce2de774a924da6947a6c4d0db514172023-12-03T11:36:00ZengPeerJ Inc.PeerJ2167-83592019-11-017e800810.7717/peerj.8008Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolutionBen Thuy0Andy Gale1Lea Numberger-Thuy2Department of Palaeontology, Natural History Museum Luxembourg, Luxembourg City, LuxembourgSchool of Earth & Environmental Sciences, University of Portsmouth, Portsmouth, UKDepartment of Palaeontology, Natural History Museum Luxembourg, Luxembourg City, LuxembourgThe genus Astrophiura, which ranks among the most extraordinary of modern brittle stars, is the type genus of the recently resurrected family Astrophiuridae within the order Ophiurida. On account of its absurdly enlarged and strongly modified lateral arm plates, Astrophiura bears a closer resemblance to a pentagonal starfish than to a typical ophiuroid. Although molecular evidence suggests an ancient origin of the Astrophiuridae, dating back at least to the Early Jurassic, not a single fossil astrophiurid has been reported so far. Here, we describe dissociated lateral arm plates from the Campanian of Cringleford near Norwich, UK, and the Maastrichtian of Rügen, Germany (both Upper Cretaceous) with unambiguous astrophiurid affinities and assign these to a new species, Astrophiura markbeneckei. This represents the first fossil record of the family. In addition, the Rügen material included lateral arm plates that superficially resemble those of A. markbeneckei sp. nov. but differ in having spine articulations that are typical of the ophionereidoid family Amphilimnidae. We assign these plates to a new genus and species, Astrosombra rammsteinensis, an extinct amphilimnid with morphological modifications similar to those of Astrophiura, and thus representing a remarkable case of parallel evolution amongst brittle stars looking like starfish.https://peerj.com/articles/8008.pdfOphiuroideaAstrophiuridaeAmphilimnidaeNew taxaCretaceousConvergent evolution |
| spellingShingle | Ben Thuy Andy Gale Lea Numberger-Thuy Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution PeerJ Ophiuroidea Astrophiuridae Amphilimnidae New taxa Cretaceous Convergent evolution |
| title | Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution |
| title_full | Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution |
| title_fullStr | Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution |
| title_full_unstemmed | Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution |
| title_short | Brittle stars looking like starfish: the first fossil record of the Astrophiuridae and a remarkable case of convergent evolution |
| title_sort | brittle stars looking like starfish the first fossil record of the astrophiuridae and a remarkable case of convergent evolution |
| topic | Ophiuroidea Astrophiuridae Amphilimnidae New taxa Cretaceous Convergent evolution |
| url | https://peerj.com/articles/8008.pdf |
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