Scaphognathus

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Scaphognathus
Temporal range: Late Jurassic, 155.7–150.8 Ma
Scaphognathus crassirostris 4.jpg
Holotype specimen
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Family: Rhamphorhynchidae
Subfamily: Scaphognathinae
Genus: Scaphognathus
Wagner, 1861
Type species
Pterodactylus crassirostris
Goldfuss, 1831
Species
  • Scaphognathus crassirostris (Goldfuss, 1831)
Synonyms

Scaphognathus was a pterosaur that lived around Germany during the Late Jurassic. It had a wingspan of 0.9 m (3 ft).

Description

Restoration

The Scaphognathus is known from three specimens, all of which originated in the Kimmeridgian-age[1] Solnhofen Limestone.[2] Physically it was very similar to Rhamphorhynchus, albeit with notable cranial differences.[2]

For one, Scaphognathus had a proportionately shorter skull (4.5 in) with a blunter tip and a larger antorbital fenestra.[2] Its teeth oriented vertically rather than horizontally. The traditional count of them held that eighteen teeth were in the upper jaws and ten in the lower.[2] S. Christopher Bennett, studying a new third specimen, SMNS 59395, in 2004 determined there were only sixteen teeth in the upper jaws, the higher previous number having been caused by incorrectly adding replacement teeth.[3]

Comparisons between the scleral rings of Scaphognathus and modern birds and reptiles suggest that it may have been diurnal. This may also indicate niche partitioning with contemporary pterosaurs inferred to be nocturnal, such as Ctenochasma and Rhamphorhynchus.[4]

Naming

A. Goldfuss' illustration of the type specimen

The first known Scaphognathus specimen was described in 1831 by August Goldfuss[5] who mistook the tailless specimen for a new Pterodactylus species: P. crassirostris.[2] The specific name means "fat snout" in Latin. This specimen was an incomplete adult with a 0.9 m (3 ft) wingspan recovered from the Solnhofen strata near Eichstätt. In 1858 Johann Wagner referred the species to Rhamphorhynchus. After recognising the fundamentally different snout shape, Wagner, after previous failed attempts by Leopold Fitzinger and Christoph Gottfried Andreas Giebel, who used preoccupied names, in 1861 named a distinct genus: Scaphognathus, derived from Greek skaphe, "boat" or "tub", and gnathos, "jaw", in reference to the blunt shape of the lower jaws.[6]

In the early twentieth century, the "rhamphorhynchoid" nature of S. crassirostris was recognized after the discovery of the second specimen in Mühlheim, whose long tail was preserved. The second Scaphognathus specimen was more complete than its predecessor, but only half the size (twenty inch wingspan) and with partially ossified bones.[2] These characters indicate that the second specimen was a juvenile.[2]

Classification

1905 restoration of Scaphognathus (right) and other pterosaurs

The cladogram (family tree) of rhamphorhynchids below is the result of a large phylogenetic analysis published by Andres & Myers in 2013.[7]

 Breviquartossa 
 Rhamphorhynchidae 

Scaphognathus crassirostris

 Rhamphorhynchinae 

Dorygnathus banthensis

Cacibupteryx caribensis

Nesodactylus hesperius

Rhamphorhynchus muensteri

Harpactognathus gentryii

Angustinaripterus longicephalus

Sericipterus wucaiwanensis

See also

References

  1. ^ Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 545–549. ISBN 0-520-24209-2.
  2. ^ a b c d e f g "Scaphognathus." In: Cranfield, Ingrid (ed.). The Illustrated Directory of Dinosaurs and Other Prehistoric Creatures. London: Salamander Books, Ltd. Pp. 308-309.
  3. ^ Bennett, S. C. (2004). "New information on the pterosaur Scaphognathus crassirostris and the pterosaurian cervical series", Journal of Vertebrate Paleontology, 24(Supplement to #3):38A
  4. ^ Schmitz, L.; Motani, R. (2011). "Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology". Science. 332 (6030): 705–8. doi:10.1126/science.1200043. PMID 21493820.
  5. ^ Goldfuss G. A. (1830). "Pterodactylus crassirostris". Isis von Oken, Jena pp. 552–553
  6. ^ Wagner, J.A. (1861). "Uebersicht über die fossilen Reptilien des lithographischen Schiefers in Bayern nach ihren Gattungen und Arten". Sitzungsberichte der königlich bayerischen Akademie der Wissenschaften zu München, 1861 Theil 1: 497–535.
  7. ^ Andres, Brian; Myers, Timothy S. (2013). "Lone Star Pterosaurs". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 103 (3–4): 383. doi:10.1017/S1755691013000303.

Literature

External links

  • The Pterosaur Database (pdf)
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