Panderichthys
| Panderichthys | |
|---|---|
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| Skull cast, Musee d'Histoire Naturelle, Lille | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Elpistostegalia |
| Family: | †Panderichthyidae Vorobyeva, 1968 |
| Genus: | †Panderichthys Gross, 1941 |
| Type species | |
| †Panderichthys rhombolepis Gross, 1941
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| Species | |
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Panderichthys is a genus of extinct sarcopterygian (lobe-finned fish). It lived in the late Devonian period, about 380 mya. Possible tetrapod tracks dating back to before the appearance of Panderichthys in the fossil record were found. This suggests that Panderichthys is not a direct ancestor of tetrapods. It shows the traits which evolved during the fish-tetrapod evolution.[1][2]
Decreased oxygen in the atmosphere would have caused the oxygen concentrations in water to decrease. This would have caused any aquatic animal which could breathe air to have an advantage, and be more likely to thrive.
In addition to its ability to swim in water, Panderichthys could also breathe air. Its strong pectoral fins might allow it to prop up its head in shallow water and take a breath.
Description
[change | change source]Panderichthys is a 1.5–2 m (4 ft 11 in–6 ft 7 in) long fish with a large tetrapod-like head that is flattened, narrow at the snout and wide in the back.
In January 2010, Nature reported well-preserved and "securely dated" tetrapod tracks from Polish marine tidal flat sediments approximately 397 million years old. These fossil tracks suggest that a group of two meter long tetrapods lived in the fully marine intertidal or lagoonal areas on the south coast of Laurussia. This implies that Panderichthys is not a transitional fossil and represents its own adaptive morphology. Therefore, Panderichthys can only be a "late-surviving relic", showing traits that evolved during the transition from fish-like creatures to tetrapods, but whose date does not reflect that transition. The tracks "force a radical reassessment of the timing, ecology and environmental setting of the fish–tetrapod transition, as well as the completeness of the body fossil record".
The humerus
[change | change source]One of the features of Panderichthys is its humerus.[source?] Due to a complex process, early tetrapods have an L-shaped humerus.[3] Another unique feature is that the humeral ridge doesn't go into the entepicondyle.[4]
Respiration
[change | change source]Panderichthys could breathe air.[source?] The opercular series in Panderichthys was shorter than in other species of osteolepiforms.[5]
Gallery
[change | change source]-
Digital life reconstruction -
Late Devonian "fishapods", including Panderichthys
References
[change | change source]- ↑ Niedzwiedzki, G., Szrek, P., Narkiewicz, K., Narkiewicz, M and Ahlberg, P., Nature 463(7227):43–48, 2010, Tetrapod trackways from the early Middle Devonian period of Poland, 7 January 2010.
- ↑ Clack, Jennifer A. "Devonian climate change, breathing, and the origin of the tetrapod stem group." Integrative and Comparative Biology 47.4 (2007): 510-523.
- ↑ Shubin, Daeschler, and Coates, N. H., E. B., and M. I. ((2004)). "The early evolution of the tetrapod humerus". Science.
{{cite web}}: Check date values in:|date=(help); Italic or bold markup not allowed in:|website=(help)CS1 maint: multiple names: authors list (link) - ↑ Boisvert,, Catherine A. ((2009)). "The humerus of Panderichthys in three dimensions and its significance in the context of the fish-tetrapod transition". Acta Zoologica.
{{cite web}}: Check date values in:|date=(help); Italic or bold markup not allowed in:|website=(help)CS1 maint: extra punctuation (link) - ↑ Clack,, Jennifer A. ((2007)). "Devonian climate change, breathing, and the origin of the tetrapod stem group". Integrative and Comparative Biology.
{{cite web}}: Check date values in:|date=(help); Italic or bold markup not allowed in:|website=(help)CS1 maint: extra punctuation (link)