Eudimorphodon

Source: Wikipedia, the free encyclopedia.

Eudimorphodon
Temporal range:
Ma
MCSNB 2888 in Bergamo
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Family: Eudimorphodontidae
Subfamily:
Eudimorphodontinae
Genus: Eudimorphodon
Zambelli, 1973
Species:
E. ranzii
Binomial name
Eudimorphodon ranzii
Zambelli, 1973

Eudimorphodon was a pterosaur that was discovered in 1973 by Mario Pandolfi in the town of Cene, Italy and described the same year by Rocco Zambelli. The nearly complete skeleton was retrieved from shale deposited during the Late Triassic (mid to late Norian stage,[1] 219-215 million years ago),[2] making Eudimorphodon one of the oldest pterosaurs known.[3] It had a wingspan of about 100 centimeters (3.3 ft)[4] and at the end of its long bony tail may have been a diamond-shaped flap like in the later Rhamphorhynchus. If so, the flap may have helped it steer while maneuvering in the air.[5] Eudimorphodon is known from several skeletons, including juvenile specimens.

Discovery and species

Fossil at Museo di Scienze Naturali, Bergamo, specimens MCSNB 8959 a,b

Eudimorphodon currently includes one species, the

Alfred Walter Crompton; the name is a diminutive because the exemplar is so small. In 2015 it was named as a separate genus Arcticodactylus by Alexander Kellner.[8] Specimen BSP 1994 I 51, in 2003 referred to a cf E. ranzii,[9] was in 2015 by Kellner made the genus Austriadraco.[8]

In 1986 fossil jaw fragments containing multicusped teeth were found in Dockum Group rocks in western Texas. One fragment, apparently from a lower jaw, contained two teeth, each with five cusps. Another fragment, from an upper jaw, also contained several multi-cusped teeth. These finds are very similar to Eudimorphodon and may be attributable to this genus, although without better fossil remains it is impossible to be sure.[1]

Many fossils have been found that once were referred to Eudimorphodon, making Eudimorphodon represent one of the most abundant pterosaurs from Italy.[10] Today, these have largely been made separate genera.[11]

Description

Restoration

Eudimorphodon was a small pterosaur, being 1 meter (3.3 ft) in length, and weighing no more than 10 kilograms (22 lb). Its fourth finger had a very large size, and attached to the membrane making up the wing.[10]

Eudimorphodon showed a strong differentiation of the teeth, hence its name, which is derived from ancient Greek for "true dimorphic tooth". It also possessed a large number of these teeth, a total of 110 of them densely packed into a jaw only 6 centimeters (2.4 in) long. The front of the jaw was filled with fangs, per side four in the upper jaw, two in the lower jaw, that rather abruptly gave way to a line of smaller multipointed teeth, 25 in the upper jaw, 26 in the lower jaw, most of which had five cusps[3]

The morphology of the teeth are suggestive of a piscivorous diet, which has been confirmed by preserved stomach contents containing the remains of fish of the genus Parapholidophorus. Young Eudimorphodon had slightly differing dentition with fewer teeth and may have had a more insectivorous diet.[3] The top and bottom teeth of Eudimorphodon came into direct contact with each other when the jaws were closed, especially at the back of the jaw. This degree of dental occlusion is the strongest known among pterosaurs. The teeth were multi-cusped, and tooth wear shows that Eudimorphodon was able to crush or chew its food to some degree. Wear along the sides of these teeth suggests that Eudimorphodon also fed on hard-shelled invertebrates.[12] The teeth distinguish Eudimorphodon, because almost all other pterosaurs either had simple teeth, or lacked them altogether. Benson et al. (2012) noticed that the teeth would have been perfect for grabbing and crushing fish.[10]

Phylogeny and classification

Despite its great age, Eudimorphodon has few primitive characteristics

prolacertiformes
.

Within the standard hypothesis that the

Campylognathoididae.[3] The following phylogenetic analysis follows the topology of Upchurch et al. (2015).[13]

Eopterosauria

Preondactylus buffarinii

Austriadactylus cristatus

Peteinosaurus zambellii

Eudimorphodontoidea
Raeticodactylidae

Raeticodactylus filisurensis

Caviramus schesaplanensis

Eudimorphodontidae

Arcticodactylus cromptonellus

Carniadactylus rosenfeldi

Eudimorphodon ranzii

In 2020 however, a study upheld by Matthew G. Baron about early pterosaur interrelationships found Eudimorphodon to group with the clade

See also

References

  1. ^ .
  2. ^ Müller R.T., Ezcurra M.D., Garcia M.S., Agnolín F.L., Stocker M.R., Novas F.E., Soares M.B., Kellner A.W.A. & Nesbitt S.J. (2023). ”New reptile shows dinosaurs and pterosaurs evolved among diverse precursors”. Nature 620(7974): p. 589–594. doi:10.1038/s41586-023-06359-z
  3. ^ a b c d e Cranfield, I. The Illustrated Directory of Dinosaurs and Other Prehistoric Creatures. London: Salamander Books, Ltd. Pp. 280–281.
  4. .
  5. .
  6. ^ Dalla Vecchia, F.M. (2009). "Anatomy and systematics of the pterosaur Carniadactylus (gen. n.) rosenfeldi (Dalla Vecchia, 1995)". Rivista Italiana de Paleontologia e Stratigrafia. 115 (2): 159–188.
  7. ^ Jenkins, F.A. Jr.; et al. (2001). "A diminutive pterosaur (Pterosauria: Eudimorphodontidae) from the Greenlandic Triassic". Bulletin of the Museum of Comparative Zoology, Harvard University. 155: 487–506.
  8. ^
    PMID 26131631
    .
  9. ^ Wellnhofer P., 2003, "A Late Triassic pterosaur from the Northern Calcareous Alps (Tyrol, Austria)". In: Buffetaut E. and Mazin J-M. (Eds), Evolution and Palaeobiology of Pterosaurs, Geological Society of London, Special Publications 217, pp 5–22
  10. ^ .
  11. .
  12. .
  13. .