''Dorsetisaurus'' is a genus of extinct
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
, known from the Late Jurassic of North America, and the Late Jurassic-earliest Cretaceous of Europe. The genus was first reported from the
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma.
Geology
Pro ...
(
Berriasian
In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago) ...
)
Lulworth Formation
The Lulworth Formation is a geologic formation in England. It dates from the late Tithonian to the mid Berriasian. It is a subunit of the Purbeck Group. In Dorset, it consists of three members, which are in ascending order, the Mupe Member, the ...
of the
Purbeck Group
The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in ...
of
Durlston Bay
Durlston Bay (also known as Durdlestone Bay) is a small bay next to a country park of the same name, just south of the resort of Swanage, on the Isle of Purbeck in Dorset, England. It has been a renowned site for Lower Cretaceous fossils since the ...
, in
Dorset
Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...
. It has also been reported from the
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the name ...
aged
Alcobaça Formation
The Alcobaça Formation, previously known as the Guimarota Formation and also known as the Consolação Unit, is a geological formation in Portugal. It dates back to the Kimmeridgian stage of the Late Jurassic. It is an important source of inform ...
of
Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
and
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic, Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandsto ...
of Western North America
[Foster, J. (2007). "Table 2.1: Fossil Vertebrates of the Morrison Formation." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. pp. 58-59.] present in stratigraphic zones 2, 4, and 5.
[Foster, J. (2007). "''Enneabatrachus hechti''" ''Jurassic West: The Dinosaurs of the Morrison Formation and Their World''. Indiana University Press. p. 137.] It is considered the oldest widely accepted member of
Anguimorpha
The Anguimorpha is a suborder of squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to '' Varanus'' and ''Anguis'' than ''Scincus''. These lizards, along with iguanians and snakes, constitute the propos ...
. based on the presence of 11 shared
synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...
.
See also
*
Paleobiota of the Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has a wide assortment of Taxon, taxa represented in its fossil record, including dinosaur fossils in North America ...
References
Jurassic lizards
Morrison fauna
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