Gracilineustes is an extinct genus of marine crocodyliform that lived in the oceans during the Middle to Late Jurassic. Gracilineustes was a carnivore that spent much, if not all, its life out at sea. It was a small reptile, with G. leedsi measuring 2.25–3.11 m (7.4–10.2 ft) long and G. acutus measuring 3.77 m (12.4 ft) long.[3]

Gracilineustes
Temporal range: Callovian - Kimmeridgian, 167–155 Ma
Fossil skull of G. leedsi, NHMUK PV R5793, at the Field Museum of Natural History
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Suborder: Thalattosuchia
Family: Metriorhynchidae
Subfamily: Metriorhynchinae
Genus: Gracilineustes
Young et al., 2010
Type species
Gracilineuestes leedsi
(Andrews, 1913)[2]
Other species
  • G. acutus Lennier, 1887 [1]
Synonyms
Holotype of G. leedsi, NHMUK PV R3540

Discovery and species

edit
 
Skull and limb of G. leedsi

Fossil specimens referrable to Gracilineustes are known from Middle-Late Jurassic deposits of England and France.[4]

Valid species

edit
  • G. leedsi: Western Europe (England) of the Middle Jurassic (Callovian);[2] Metriorhynchus laeve is a junior synonym.
  • G. acutus: Western Europe (France) of the Late Jurassic (Kimmeridgian) [1]

References

edit
  1. ^ a b Lennier G. 1887. Description des fossiles du Cap de la Hève. Bulletin de la Société Géologique de Normandie, Le Havre 12: 17-98.
  2. ^ a b Andrews CW. 1913. A descriptive catalogue of the marine reptiles of the Oxford Clay, Part Two. London: British Museum (Natural History), 206 pp.
  3. ^ Young, M.T.; Bell, M.A.; de Andrade, M.B.; Brusatte, S.L. (2011). "Body size estimation and evolution in metriorhynchid crocodylomorphs: implications for species diversification and niche partitioning". Zoological Journal of the Linnean Society. 163 (4): 1199–1216. doi:10.1111/j.1096-3642.2011.00734.x.
  4. ^ Young, Mark T., Brusatte, Stephen L., Ruta, M., Andrade, Marco B. 2009. "The evolution of Metriorhynchoidea (Mesoeucrocodylia, Thalattosuchia): an integrated approach using geometrics morphometrics, analysis of disparity and biomechanics". Zoological Journal of the Linnean Society 158: 801-859.