Spinosaurinae

Stromer, 1915 Type genus Spinosaurus

Its genera lived 121.4–93.9 million years ago Early Cretaceous–Late Cretaceous

Early Cretaceous and Late Cretaceous stages

Spinosaurinae is one of the two subfamilies of spinosaurids, the large, crocodile-snouted theropod dinosaurs, and forms the sister group to Baryonychinae. Its members — including Spinosaurus, Irritator, Ichthyovenator, Oxalaia, and Sigilmassasaurus, along with Iberian forms such as Vallibonavenatrix — are marked by straight, conical, unserrated teeth and by nostrils set even further back on the skull than in baryonychines. Spinosaurines include the largest and most specialized spinosaurids, and appear to have evolved across the southern landmasses of Gondwana, in Africa and South America, during the Cretaceous. In several members the tall, reclined neural spines and elongated chevrons of the tail formed a deep, paddle-like structure — most pronounced in Spinosaurus — that has been linked to a semiaquatic lifestyle. Their jaws and teeth were well suited to processing the meat of relatively large vertebrate prey, not just fish.

Diagnosis

Straight, conical tooth crowns lacking recurvature and serrations
Widely spaced dentary tooth crowns
Strongly reduced first premaxillary tooth
External nares retracted farther posteriorly than in baryonychines

Genera placed directly in Spinosaurinae

Ichthyovenator Allain et al., 2012 Aptian (121.4–113.2 Ma)Laos
Irritator Martill et al., 1996 Aptian–Albian (121.4–100.5 Ma)Brazil
Oxalaia Disputed Kellner et al., 2011 Cenomanian (100.5–93.9 Ma)Brazil
Sigilmassasaurus Disputed Russell, 1996 Cenomanian (100.5–93.9 Ma)Morocco
Spinosaurus Stromer, 1915 Cenomanian (100.5–93.9 Ma)Morocco

References

Stromer, E. (1915). Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. II. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen., nov. spec. [Results of Prof. E. Stromer's research expeditions in the deserts of Egypt. II. Vertebrate remains of the Baharije Stage (lowermost Cenomanian). 3. The original of the theropod Spinosaurus aegyptiacus nov. gen., nov. spec.]. Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse 28(3): 1-32.
Named the family Spinosauridae, from which the subfamily Spinosaurinae takes its authorship by coordination.
stromer1915a
Sereno, P. C.; Beck, A. L.; Dutheil, D. B.; Gado, B.; Larsson, H. C. E.; Lyon, G. H.; Marcot, J. D.; Rauhut, O. W. M.; Sadleir, R. W.; Sidor, C. A.; Varricchio, D. D.; Wilson, G. P.; Wilson, J. A. (1998). A Long-Snouted Predatory Dinosaur from Africa and the Evolution of Spinosaurids. Science 282(5392): 1298-1302. American Association for the Advancement of Science (AAAS). doi:10.1126/science.282.5392.1298 sereno1998b