Dactylosaurus
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| Genus: | Dactylosaurus Gürich, 1884
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Dactylosaurus is a genus of nothosaur in the family Pachypleurosauridae. Along with Anarosaurus, Dactylosaurus was one of the earliest known pachypleurosaurs to come from Europe.[1]
Etymology
Dactylosaurus comes from the Greek daktulos (δακτυλος), "finger" and sauros (σαυρος), meaning "lizard" or "reptile."
Description
The nasal bones of Dactylosaurus meet and are broadly structured.[2] The upper temporal fenestra is large and kidney-shaped.[2] There are 17 cervical vertebrae[2] and the cervical ribs have anterior processes.[2] The maxillae of Dactylosaurus extended broadly up the side of the snout.[1]
D. gracilis
The holotype specimen (MGUWR WR 3871s) of D. gracilis was only a partial skeleton, consisting of the anterior end alone.[1] Because it differed slightly from the fossils of D. gracilis, it was first thought to belong to the species D. schroederi,[1] which is now considered a junior synonym for juvenile D. gracilis.[2] Once this was established, the juvenile fossil, which was found before the adult fossils, became the holotype. The one limb that was found (a left forelimb), was noted to have a slimmer radius and ulna than Neusticosaurus,[1] a similar nothosaur from Europe.[1] D. gracilis is the smallest known species in its family,[1] which includes the much more recognized Keichousaurus, a nothosaur often remembered for its small size.[3] The original holotype of D. gracilis is considered a juvenile,[2] however the size of a nothosaur when its bones harden is used to show size, making the estimate as smallest member of its family still valid.[1]
Distribution
Dactylosaurus lived in the Middle Triassic period during the Anisian faunal stage, of central Europe.[4] In terms of geology, they are found in the lowest Muschelkalk layers, in and around the Gogolin Formation.[4]
References
- ^ a b c d e f g h Lepidosauromorpha: Pachypleurosauridae: Dactylosaurus & Anarosaurus Palaeos.com. Last accessed 2008-07-04. Cite error: The named reference "paleos" was defined multiple times with different content (see the help page).
- ^ a b c d e f Rieppel, O & L Kebang (1995), "Pachypleurosaurs (Reptilia, Sauropterygia) from the Lower Muschelkalk, and a review of the Pachypleurosauroidea." Fieldiana Geol. N.S. 32: 1-44.
- ^ "peripatus.gen.nz entry on Keichousaurus". Retrieved 2008-06-12.
- ^ a b "plesiosauria.com entry on Dactylosaurus". Retrieved 2008-06-13.
External links
- Pachypleurosauridae from Palaeos.com (technical)
- Dactylosaurus from the Plesiosaur Directory
