Parvipelvia (

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for "little pelvis" - ''parvus'' meaning "little" and ''pelvis'' meaning "pelvis") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of euichthyosaur

ichthyosaur Ichthyosaurs (Ancient Greek for "fish lizard" – and ) are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia ('fish flippers' – a designation introduced by Sir Richard Owen in 1842, altho ...

s that existed from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

to the early

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

(middle

Norian The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian. Stratigraphic defi ...

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

) of

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. Named by Ryosuke Motani, in 1999, it contains the basal taxa like '' Macgowania'' and '' Hudsonelpidia''. Maisch and Matzke (2000) found in their analysis seven synapomorphies that support Parvipelvia. They also found 10 synapomorphies that support the existence of post-Triassic clade of ichthyosaurs (all parvipelvians excluding ''Macgowania'' and ''Hudsonelpidia''), for which the name Neoichthyosauria was found to be available. Parvipelvians were the only ichthyosaurs to survive the Triassic-Jurassic extinction event.

Phylogeny

Parvipelvia is a

node-based taxon Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which ...

defined in 1999 as "the last common ancestor of ''Hudsonelpidia'', ''Macgowania'', ''

Ichthyosaurus ''Ichthyosaurus'' (derived from Greek ' () meaning 'fish' and ' () meaning 'lizard') is a genus of ichthyosaurs from the Early Jurassic (Hettangian - Pliensbachian), with possible Late Triassic record, from Europe ( Belgium, England, Germany, ...

'' and all of its descendants". Maisch and Matzke (2000) also defined Neoichthyosauria which is a node-based taxon originally named by P. Martin Sander in 2000, as "the last common ancestor of ''

Temnodontosaurus trigonodon ''Temnodontosaurus'' (Greek for "cutting-tooth lizard"temno, meaning "to cut", odont meaning "tooth" and sauros meaning "lizard") is an extinct genus of ichthyosaur from the Early Jurassic period. They lived between 200 and 175 million years ag ...

'' and ''

Ophthalmosaurus icenicus ''Ophthalmosaurus'' (meaning "eye lizard" in Greek) is an ichthyosaur of the Jurassic period (165–150 million years ago). Possible remains from the Cretaceous, around 145 million years ago, are also known. It was a relatively medium-sized icht ...

'' and all of its descendants". The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

s below follows Motani (1999) and Maisch and Matzke (2000).

References

Ichthyosaurs Late Triassic ichthyosaurs Early Jurassic ichthyosaurs Middle Jurassic ichthyosaurs Late Jurassic ichthyosaurs Early Cretaceous ichthyosaurs Late Cretaceous ichthyosaurs Norian first appearances Turonian extinctions Cretaceous reptiles of Asia Cretaceous reptiles of Australia Cretaceous reptiles of Europe Early Cretaceous reptiles of North America Late Cretaceous reptiles of North America Cretaceous reptiles of South America Jurassic reptiles of Asia Jurassic reptiles of Europe Early Jurassic reptiles of North America Middle Jurassic reptiles of North America Late Jurassic reptiles of North America Jurassic reptiles of South America Late Triassic reptiles of Asia Late Triassic reptiles of Europe Late Triassic ichthyosaurs of North America Late Triassic reptiles of South America Ichthyosaurs of Europe {{ichthyosaur-stub