page_title: Spinosaurus
section_title: Phylogeny
hierarchical_section_title: Spinosaurus / Classification / Phylogeny
caption_attribution_description: English: Anachronistic comparison of four spinosaurid species, clockwise from the left: Suchomimus tenerensis, Spinosaurus aegyptiacus, Irritator challengeri, and Baryonyx walkeri.
context_page_description: Spinosaurus is a genus of spinosaurid dinosaur that lived in what now is North Africa during the upper Albian to upper Turonian stages of the Cretaceous period, about 112 to 93.5 million years ago. This genus was known first from Egyptian remains discovered in 1912 and described by German paleontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material has come to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon. Another possible junior synonym is Oxalaia from the Alcântara Formation in Brazil.
  Spinosaurus was among the largest of all known carnivorous dinosaurs, nearly as large as or even larger than other theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus.
context_section_description: The subfamily Spinosaurinae was named by Sereno in 1998, and defined by Holtz and colleagues (2004) as all taxa closer to Spinosaurus aegyptiacus than to Baryonyx walkeri. And the subfamily Baryonychinae was named by Charig & Milner in 1986. They erected both the subfamily and the family Baryonychinae for the newly discovered Baryonyx, before it was referred to the Spinosauridae. Their subfamily was defined by Holtz and colleagues in 2004, as the complementary clade of all taxa closer to Baryonyx walkeri than to Spinosaurus aegyptiacus. Examinations by Marcos Sales and Cesar Schultz and colleagues (2017) indicate that the South American spinosaurids Angaturama, Irritator, and Oxalaia were intermediate between Baronychinae and Spinosaurinae based on their craniodental features and cladistic analysis. This indicates that Baryonychinae may in fact be non-monophyletic. Their cladogram can be seen below.
   
  The cladogram below depicts the findings of Arden and colleagues (2018):
caption: Restoration of various spinosaurids that did not live in the same time or space
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