Biology:Palaeospondylus
| Palaeospondylus Temporal range: Template:Fossil range/linked
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| Fossil on display at the Cincinnati Museum Center | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Subphylum: | Vertebrata
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| Genus: | Palaeospondylus Traquair, 1890
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| Species: | P. gunni
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| Binomial name | |
| Palaeospondylus gunni Traquair, 1890
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Palaeospondylus ("early vertebrae") is a fish-like fossil vertebrate. Its fossils are described from the Achanarras slate quarry in Caithness, Scotland.
The fossil as preserved is carbonized, and indicates an eel-shaped animal up to 6 centimetres (2 in) in length. The skull, which must have consisted of hardened cartilage, exhibits pairs of nasal and auditory capsules, with a gill apparatus below its hinder part, and ambiguous indications of ordinary jaws.[citation needed]
The phylogeny of this fossil has puzzled scientists since its discovery in 1890, and many taxonomies have been suggested. In 2004, researchers proposed that Palaeospondylus was a larval lungfish.[1] Previously, it had been classified as a larval tetrapod, unarmored placoderm, an agnathan, an early stem hagfish, and a chimera.[2][3] A 2017 study suggested that it was a stem chondrichthyan.[4]
In 2022, researchers report, based on studies using synchrotron radiation X-ray micro-computed tomography, that the neurocranium of Palaeospondylus was similar to those of the stem-tetrapods Eusthenopteron and Panderichthys, and concluded that Palaeospondylus was between those two phylogenetically.[5]
See also
- Orcadian Basin
References
- ↑ Thomson, K.S. (2004). "A Palaeontological Puzzle Solved?". American Scientist 92 (3): 209–211. doi:10.1511/2004.47.3425.
- ↑ Palmer, D., ed (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 33. ISBN 1-84028-152-9.
- ↑ Hirasawa, T; Oisi, Y; Kuratani, S (2016). "Palaeospondylus as a primitive hagfish". Zoological Letters 2 (1): 20. doi:10.1186/s40851-016-0057-0. PMID 27610240.
- ↑ Johanson, Zerina; Smith, Moya; Sanchez, Sophie; Senden, Tim; Trinajstic, Kate; Pfaff, Cathrin (2017). "Questioning hagfish affinities of the enigmatic Devonian vertebrate Palaeospondylus". Royal Society Open Science 4 (7): 170214. doi:10.1098/rsos.170214. PMID 28791148. Bibcode: 2017RSOS....470214J.
- ↑ Hirasawa, Tatsuya (25 May 2022). "Morphology of Palaeospondylus shows affinity to tetrapod ancestors". Nature 50 (7912): 109–112. doi:10.1038/s41586-022-04781-3. https://www.nature.com/articles/s41586-022-04781-3. Retrieved 25 May 2022.
Wikidata ☰ Q3889332 entry
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