Saichangurvel

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Saichangurvel
Temporal range: Late Cretaceous
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Clade: Gobiguania
Genus: Saichangurvel
Conrad and Norell, 2007
Type species
Saichangurvel davidsoni
Conrad and Norell, 2007

Saichangurvel (meaning "beautiful lizard" in Mongolian) is an extinct genus of iguanian lizards from the Late Cretaceous of Mongolia. It is a member of a clade called Gobiguania, an exclusively Late Cretaceous group of iguanian lizards that was likely endemic to the Gobi Desert. The type species, Saichangurvel davidsoni, was named by paleontologists Jack Conrad and Mark Norell of the American Museum of Natural History in 2007. It is known from a single nearly complete and fully articulated skeleton called IGM 3/858, which was found eroding from a block of sandstone during a thunderstorm at a fossil locality called Ukhaa Tolgod. [1] IGM 3/858 comes from the Djadochta Formation, which is between 75 and 71 million years in age. [2] Just as it is today, the Gobi was a desert during the Cretaceous. IGM 3/858 may have died in a collapsing sand dune, the rapid burial preserving its skeleton in pristine condition. [1]

Saichangurvel has a lightly built skull with a short snout and large eye sockets. It differs from other gobiguanians such as Ctenomastax and Temujinia in that it has a large uncalcified region (a fontanelle) around an opening in its skull roof called the pineal foramen. It also lacks the large caniniform teeth seen in some other gobiguanians. [1] Below is a cladogram from Daza et al. (2012) showing its phylogenetic relationships with other gobiguanians: [3]

Iguania

Hoyalacerta sanzi

Huehuecuetzpalli mixtecus

Pristiguana brasiliensis

Chamaeleontiformes

Priscagamidae

Acrodonta

Iguanoidea  (=Pleurodonta)
Silvaiguana

Hoplocercidae

Polychrotidae

Polrussia mongoliensis

Igua minuta

Isodontosaurus gracilis

Anchaurosaurus gilmorei

Zapsosaurus sceliphros

Saichangurvel davidsoni

Temujinia ellisoni

Ctenomastax parva

Euiguana

Corytophanidae

Terraiguana

Iguanidae

Crotaphytidae

Phrynosomatidae

Opluridae

Uquiasaurus

Liolaemidae

Leiocephalus

Tropiduridae

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Igua is an extinct genus of iguanian lizards belonging to a group called Gobiguania that was endemic to the Gobi Desert during the Late Cretaceous. The type species Igua minuta was named in 1991 on the basis of a skull from the Barun Goyot Formation in Mongolia. The skull itself is very small, only 14 millimetres (0.55 in) long, and may have belonged to a juvenile given that it possesses a large fontanelle and that many of the bones are unfused. The snout-vent length of the individual is estimated to have been 55 to 65 millimetres. Igua differs from related gobiguanians like Polrussia in having a more rounded skull. It is similar in appearance to the living genera Liolaemus and Tropidurus. The teeth are tricuspid and pleurodont, meaning they are attached to inner surfaces of the jaws.

Magnuviator is a genus of extinct iguanomorph lizard from the Late Cretaceous of Montana, US. It contains one species, M. ovimonsensis, described in 2017 by DeMar et al. from two specimens that were discovered in the Egg Mountain nesting site. Magnuviator is closest related to the Asian Saichangurvel and Temujinia, which form the group Temujiniidae. Unlike other members of the Iguanomorpha, however, Magnuviator bears a distinct articulating notch on its tibia for the ankle bones, which has traditionally been considered a characteristic of non-iguanomorph lizards. The morphology of its teeth suggests that its diet would have mainly consisted of wasps, like the modern phyrnosomatid iguanians Callisaurus and Urosaurus, although it also shows some adaptations to herbivory.

References

  1. 1 2 3 Conrad, J. L.; Norell, M. A. (2007). "A Complete Late Cretaceous Iguanian (Squamata, Reptilia) from the Gobi and Identification of a New Iguanian Clade". American Museum Novitates. 3584: 1. doi:10.1206/0003-0082(2007)3584[1:ACLCIS]2.0.CO;2. hdl:2246/5877.
  2. Godefroit, Pascal; Currie, Philip J.; Hong, Li; Yong, Shang Chang; Zhi-Ming, Dong (2008). "A new species of Velociraptor(Dinosauria: Dromaeosauridae) from the Upper Cretaceous of northern China". Journal of Vertebrate Paleontology. 28 (2): 432. doi:10.1671/0272-4634(2008)28[432:ANSOVD]2.0.CO;2.
  3. Daza, J. D.; Abdala, V.; Arias, J. S.; García-López, D.; Ortiz, P. (2012). "Cladistic Analysis of Iguania and a Fossil Lizard from the Late Pliocene of Northwestern Argentina". Journal of Herpetology. 46: 104–119. doi:10.1670/10-112.