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Description

Irritator is a genus of spinosaurid theropod dinosaur that lived during the Early Cretaceous Period, of what is now Brazil. Current estimates indicate a length of between 7.5 to 8 meters. It is only known from a partial skull from the Romualdo Member of the Santana Formation (around 110 million years old).

Some sources consider Angaturama limai to be a synonym of Irritator, citing the fact that the remains of Angaturama seem to complete Irritator's skull. However, substantial objection has been raised to this assertion. Kellner and Campos (2000) and Machado and Kellner (2005) both suggest that the fossils come from two different genera, and that the fossil of Angaturama was clearly more laterally flattened than Irritator. A review of both fossils by Sales and Schultz (2017) also noted that the specimens differ in other aspects of their preservation: the Irritator specimen is brighter in colour etc. Nevertheless, although the two specimens evidently do not belong to the same individual, Sales and Schultz noted that synonymy at the genus level would need to be verified by more extensively overlapping remains.

Exploring the possibility that Irritator is synonymous with Angaturama (which lived in the same time and the same place), I have reconstructed the animal here using known material from both genera. Despite the way the Angaturama premaxilla curiously seems to complete Irritator's skull, I find it dubious to think that these remains could belong to the same individual specimen. But if Angaturama and Irritator are eventually regarded as members of the same genus, Irritator challengeri would have priority, so I have titled this piece as such.

*Update: A 2017 paper was brought to my attention that suggests that the holotypes of Irritator and Angaturama actually overlap (the last tooth preserved on Angaturama and the first tooth preserved on Irritator are the same tooth position). This is also evidence that while the two specimens may belong to the same genus, they cannot belong to the same individual. So I updated this sketch accordingly.
Source: Spinosaur taxonomy and evolution of craniodental features: Evidence from Brazil 2017

I also updated the Angaturama premaxilla after finally finding a fantastic image of this specimen online.

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This work is covered under copyright law. You may not use my work for layouts, blogs, websites, facebook pages (or the like), banners, designs, posters, CD, books etc… without receiving permission or a license from me. My work is not stock photography. If I find that my work is being used illegally, then legal action will be taken. If you see my work being used, please E-mail me right away.
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Description

Irritator is a genus of spinosaurid theropod dinosaur that lived during the Early Cretaceous Period, of what is now Brazil. Current estimates indicate a length of between 7.5 to 8 meters. It is only known from a partial skull from the Romualdo Member of the Santana Formation (around 110 million years old).

Some sources consider Angaturama limai to be a synonym of Irritator, citing the fact that the remains of Angaturama seem to complete Irritator's skull. However, substantial objection has been raised to this assertion. Kellner and Campos (2000) and Machado and Kellner (2005) both suggest that the fossils come from two different genera, and that the fossil of Angaturama was clearly more laterally flattened than Irritator. A review of both fossils by Sales and Schultz (2017) also noted that the specimens differ in other aspects of their preservation: the Irritator specimen is brighter in colour etc. Nevertheless, although the two specimens evidently do not belong to the same individual, Sales and Schultz noted that synonymy at the genus level would need to be verified by more extensively overlapping remains.

Exploring the possibility that Irritator is synonymous with Angaturama (which lived in the same time and the same place), I have reconstructed the animal here using known material from both genera. Despite the way the Angaturama premaxilla curiously seems to complete Irritator's skull, I find it dubious to think that these remains could belong to the same individual specimen. But if Angaturama and Irritator are eventually regarded as members of the same genus, Irritator challengeri would have priority, so I have titled this piece as such.

*Update: A 2017 paper was brought to my attention that suggests that the holotypes of Irritator and Angaturama actually overlap (the last tooth preserved on Angaturama and the first tooth preserved on Irritator are the same tooth position). This is also evidence that while the two specimens may belong to the same genus, they cannot belong to the same individual. So I updated this sketch accordingly.
Source: Spinosaur taxonomy and evolution of craniodental features: Evidence from Brazil 2017

I also updated the Angaturama premaxilla after finally finding a fantastic image of this specimen online.

COPYRIGHT NOTICE ©
This work is covered under copyright law. You may not use my work for layouts, blogs, websites, facebook pages (or the like), banners, designs, posters, CD, books etc… without receiving permission or a license from me. My work is not stock photography. If I find that my work is being used illegally, then legal action will be taken. If you see my work being used, please E-mail me right away.
Please respect copyrights.