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Temporal range: Early Cretaceous, Aptian
Ichthyovenator laosensis.jpg
Casts of the type vertebrae in side view
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Spinosauridae
Subfamily: Spinosaurinae
Genus: Ichthyovenator
Allain et al., 2012
Type species
Ichthyovenator laosensis
Allain et al., 2012

Ichthyovenator was a meat-eating theropod dinosaur. It was from the Early Cretaceous, about 113 to 125 million years ago. Its fossils were found in Laos in 2010.[1] Ichthyovenator was a spinosaurid, they were crocodile-like dinosaurs that ate fish.[2]

It is one of three spinosaurids found in Asia, the other two are Siamosaurus, and "Sinopliosaurus" fusuiensis.[1][3][4]

Discovery and naming[change | change source]

Some of the known bones of Ichthyovenator, the holotype specimen is in white and undescribed fossils are in red

The first parts of the skeleton were found in 2010. They include: One rib, part of the animal's backbones (or vertebra), and most hip bones. They did not find the skull.

The only known species is Ichthyovenator laosensis. It was named and described by Ronan Allain and his colleagues in 2012. It was found in the Grès supérieurs Formation.

The name Ichthyovenator comes from the Greek word for "fish" and the Latin word for "hunter", The name refers to the fact that it ate fish. The species name is laosensis, because it lived in what is now Laos.[1]

While Ichthyovenator was being described, paleontologists were still digging up more of its bones.[1]

Ronan Allain was one of Ichthyovenator's original describers. In 2014, he mentioned that more of Icthyovenator's skeleton was dug up in 2012. He wrote this in the Journal of Vertebrate Paleontology. These new bones include: several teeth, a hip bone, most neck bones, and a few back and tail bones. The description of the new bones has not been officially published.[5]

In 2015, some of Ichthyovenator's bones were compared to the ones of Sigilmassasaurus. Sigilmassasaurus is another spinosaurid.[6]

Description[change | change source]

Size of Ichthyovenator (in turquoise, first from right) and other spinosaurids compared to a human

Paleontologists estimate Ichthyovenator was about 8.5 metres (28 feet) long. That's about as big as Baryonyx, one of its close relatives.

It had a half-meter sail or hump on its back, similar to Suchomimus, or Spinosaurus.[7] Ichthyovenator's sail was unusual because it was split in two at the hips. Scientists don't know why it was like that.[1]

Classification[change | change source]

Speculative life restoration of Ichthyovenator laosensis, the head and limbs are based on relatives

Ichthyovenator was first classified as a spinosaurid, inside the subfamily baryonychinae. This is the same subfamily that includes Baryonyx and Suchomimus.[1]

In 2014 it was found that Ichthyovenator was part of the subfamily spinosaurinae instead. This was because of specific features on its teeth, and because its backbones look much like the ones of Sigilmassasaurus.[5][8]

Some sources say Ichthyovenator might not have been a spinosaurid. They say it may have been a sail-backed carcharodontosaurid, and that it was related to Concavenator. But this hypothesis has not been published in an academic place.[9]

The diagram below is called a cladogram. It shows how Ichthyovenator is related to other dinosaurs in its family tree. This cladogram is by Allain et al. (2012):[1]


TorvosaurusTorvosaurus tanneri Reconstruction (Flipped).png

EustreptospondylusEustrept1DB1 (Flipped).jpg

DubreuillosaurusDubreuillosaurus NT Flipped.png

Afrovenator Afrovenator Abakensis by PaleoGeek.jpg


IrritatorIrritator Life Reconstruction.jpg

SpinosaurusSpinosaurus by Joschua Knüppe.png

Ichthyovenator Ichthyovenator laosensis life reconstruction by PaleoGeek (flipped).png

SuchomimusSuchomimustenerensis (Flipped).png

BaryonyxBaryonyx walkeri restoration.jpg

References[change | change source]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Allain, R.; Xaisanavong, T.; Richir, P.; Khentavong, B. (2012). "The first definitive Asian spinosaurid (Dinosauria: Theropoda) from the early cretaceous of Laos". Naturwissenschaften. 99 (5): 369–377. Bibcode:2012NW.....99..369A. doi:10.1007/s00114-012-0911-7. PMID 22528021. S2CID 2647367.
  2. Rayfield, Emily J. 2011. “Structural Performance of Tetanuran Theropod Skulls, with Emphasis on the Megalosauridae, Spinosauridae and Carcharodontosauridae.” Special Papers in Palaeontology 86 (November). https://www.researchgate.net/publication/250916680_Structural_performance_of_tetanuran_theropod_skulls_with_emphasis_on_the_Megalosauridae_Spinosauridae_and_Carcharodontosauridae.
  3. Buffetaut, E.; and Ingevat, R. (1986). Unusual theropod dinosaur teeth from the Upper Jurassic of Phu Wiang, northeastern Thailand. Rev. Paleobiol. 5: 217-220.
  4. Buffetaut, E.; Suteethorn, V.; Tong, H.; Amiot, R. (2008). "An Early Cretaceous spinosaur theropod from southern China". Geological Magazine. 145 (5): 745–748. Bibcode:2008GeoM..145..745B. doi:10.1017/S0016756808005360. S2CID 129921019.
  5. 5.0 5.1 Allain, Ronan (2014). "New material of the theropod Ichthyovenator from Ban Kalum type locality (Laos): Implications for the synonymy of Spinosaurus and Sigilmassasaurus and the phylogeny of Spinosauridae". Journal of Vertebrate Paleontology Programs and Abstracts. Archived from the original on 2018-04-25. Retrieved 2018-04-27.
  6. Evers, Serjoscha W.; Rauhut, Oliver W.M.; Milner, Angela C.; McFeeters, Bradley; Allain, Ronan (2015-10-20). "A reappraisal of the morphology and systematic position of the theropod dinosaur Sigilmassasaurus from the "middle" Cretaceous of Morocco". PeerJ. 3: e1323. doi:10.7717/peerj.1323. ISSN 2167-8359. PMID 26500829. S2CID 7848844.
  7. Hecht, Jeff. 1998. “Fish Swam in Fear.” New Scientist. November 21. https://www.newscientist.com/article/mg16021610-300-fish-swam-in-fear/.
  8. Evers, Serjoscha W.; Rauhut, Oliver W.M.; Milner, Angela C.; McFeeters, Bradley; Allain, Ronan (2015-10-20). "A reappraisal of the morphology and systematic position of the theropod dinosaur Sigilmassasaurus from the "middle" Cretaceous of Morocco". PeerJ. 3: e1323. doi:10.7717/peerj.1323. ISSN 2167-8359. PMC 4614847. PMID 26500829.
  9. Mortimer, Mickey (2017). "Megalosauroidea". The Theropod Database.

Other websites[change | change source]

Data related to Ichthyovenator at Wikispecies