Siamosaurus: Early Cretaceous spinosaurid known from isolated teeth in Thailand
Siamosaurus, an Early Cretaceous spinosaurid from Thailand known only from isolated teeth, points to a fish-eating, partly aquatic lifestyle, but its size and exact classification remain uncertain.
Siamosaurus (literally "Siamese lizard") is a genus of carnivorous theropod dinosaur that lived during the Early Cretaceous in what is now Thailand. Only isolated tooth specimens have been attributed to this animal, so many details of its anatomy and proportions remain unknown.
Image gallery
10 Images
Discovery and remains
The material referred to this genus consists exclusively of fossil teeth recovered from Cretaceous deposits. Because the only fossils are teeth, estimates of overall body size are uncertain; some authors have suggested it could have reached roughly 9.1 metres (about 30 ft) in length, but such figures are tentative and depend on how the teeth are interpreted.
Feeding and ecology
The teeth assigned to this genus resemble those of large, long-snouted spinosaurids such as Spinosaurus, which has led most researchers to infer a mainly piscivorous diet — that is, a diet focused on fish. Tooth shape and wear patterns are consistent with catching and holding slippery prey rather than crushing bone.
A 2010 investigation led by Roman Amiot compared chemical and anatomical features of teeth from several spinosaurids (including genera like Baryonyx, Irritator, Siamosaurus and Spinosaurus) with those of other meat-eating dinosaurs. The authors concluded that spinosaurids show evidence of a partially aquatic, or semiaquatic, mode of life and probably frequented habitats similar to those used by modern large semiaquatic animals:
Such a lifestyle would have allowed spinosaurids to exploit aquatic prey while coexisting with other large terrestrial predators without direct competition for the same food resources.
Classification and uncertainties
Siamosaurus is usually placed among the spinosaurid-line theropods, but because it is known only from teeth, its exact relationships and the validity of the genus remain subjects of debate. Additional, more complete remains would be required to confirm its anatomy, ecology, and precise position within spinosaurids.
Questions and answers
Q: What is Siamosaurus?
A: Siamosaurus is a carnivorous theropod dinosaur from the Early Cretaceous of Thailand.
Q: What is known about the size of Siamosaurus?
A: It is only known from fossil teeth, so paleontologists don't know much about its size, but it might have reached a length of 9.1 meters (30 ft).
Q: What did Siamosaurus eat?
A: The teeth that were discovered looked a lot like those of Spinosaurus, so it probably ate fish.
Q: What did a study made in 2010 by Roman Amiot and his colleagues find out about spinosaurids?
A: The study found that spinosaurids had very semiaquatic (living partly in water, and partly on land) lifestyles.
Q: What habitats did spinosaurids live in?
A: They lived in habitats like those of hippopotamuses, crocodiles, and turtles.
Q: What does the semiaquatic lifestyle of spinosaurids mean?
A: It means they could exist at the same time and place as other large predators without competing for food.
Q: What other meat-eating dinosaurs were compared in the 2010 study by Roman Amiot and his colleagues besides spinosaurids?
A: Other meat-eating dinosaurs were compared to spinosaurids like Baryonyx, Irritator, and Spinosaurus.
Related articles
Author
AlegsaOnline.com Siamosaurus: Early Cretaceous spinosaurid known from isolated teeth in Thailand Leandro Alegsa
URL: https://en.alegsaonline.com/art/90151
Sources
- doi.org : 10.1130/G30402.1