''Platypterygius'' is a historically

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

genus of

platypterygiine Platypterygiinae is an extinct subfamily of ophthalmosaurid thunnosaur ichthyosaurs from the early Late Jurassic to the early Late Cretaceous (Kimmeridgian - Cenomanian) of Asia, Australia, Europe, North America and South America. Currentl ...

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 ...

from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

period. It was historically used as a

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...

, and most species within ''Platypterygius'' likely are undiagnostic at the genus or species level, or represent distinct genera, even being argued as invalid. While fossils referred to ''Platypterygius'' have been found throughout different continents, the holotype specimen was found in Germany.

Description

As ''Platypterygius'' contains multiple species not especially close to each other, little can be said in terms of shared characteristics. According to an analysis by Fischer (2012), all anatomical features used to unify ''Platypterygius'' species are either not actually present in each species, or much more widespread among unrelated ophthalmosaurs. Generally, species referred to this genus were large bodied macropredators based on their robust dentition. This is also supported by ''P. australis'' having been found with remains of

sea turtles Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, ...

and

birds Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

(specifically, of the genus ''

Nanantius ''Nanantius'' is a genus of extinct enantiornithean avialan ("bird" in the broad sense of the word) known from the Early Cretaceous (Albian, c. 100–112 mya) of Australia. Specimens and species The only valid species of ''Nanantius'' is ''N ...

'') in its guts, as well as an unidentified

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

fossil with tooth marks that may be from this genus. ''P. platydactylus'' is a large ichthyosaur, up to in length. In 2022, Gregory S. Paul estimated the size of each species except for the type species. He estimated the size of ''"P." americanus'' at in length and in body mass, ''"P." austrails'' at and , and ''"P." hercynicus'' at and .

Discovery and species

The type species of ''Platypterygius'' was described in 1922 based on remains found in upper

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

strata around

Hannover Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German States of Germany, state of Lower Saxony. Its 535,932 (2021) inhabitants make it the List of cities in Germany by population, 13th-largest city in Germa ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. These remains however were not adequately described and to complicate matters further, destroyed during

World War 2 World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

. In the time after its discovery however ''Platypterygius'' has become a catch-all genus for Cretaceous ichthyosaurs, creating the misconstrued view of post-Jurassic ichthyosaurs as being a single global genus lacking in diversity. Later research conducted in the 2000s and 2010s has repeatedly shown this to be false, with all of the autapomorphies previously used to define ''Platypterygius'' either not being present in all assigned species or also being present in other ophthalmosaurids. As the holotype was destroyed, a redescription of the material attempting to identify valid autapomorphies is out of the question and leaves the genus in a problematic state. Furthermore, the inclusion of later described genera of Cretaceous, ''platypterygiine'' ichthyosaurs has shown ''Platypterygius'' to be paraphyletic, with the different species not clading closely to one another. Subsequently, many redescriptions of referred ''Platypterygius'' species have found them to be their own distinct genera. One notable attempt at revising ''Platypterygius'' was conducted by Arkhangel'sky in 1998, who split the genus into 3 new subgenera. ''Longirostria'' (including the Australian ''"P." longmani'', a synonym of ''"P." australis'', and the Argentinian ''"P." hautali''), ''Tenuirostria'' (''"P." americanus'') and ''Pervushovisaurus'' (which included the newly described ''"P." bannovkensis''). Both ''Platypterygius platydactylus'',''"P." kiprianoffi'' and ''"P." hercynicus'' were placed in the subgenus ''Platypterygius''. ''"Platypterygius" bannovkensis'' was eventually elevated to its own genus ''Pervushovisaurus'' in 2014, utilizing Arkhangel'sky's proposed subgenus name and ''"P." campylodon'' was also assigned to this genus by a study published in 2016. ''"P." kiprianoffi'' was also assigned to ''P. campylodon'' (now ''Pervushovisaurus''). ''

Simbirskiasaurus ''Simbirskiasaurus'' is an extinct genus of ichthyosaur from the Early Cretaceous (early Barremian) of Ulyanovsk Oblast, Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Nort ...

'' was originally described in 1985 and later sunk into ''Platypterygius'' before being declared distinct in the same paper as ''Pervushovisaurus''. ''"Platypterygius" ochevi'', described in 2008 by Arkhangel'sky ''et al.'', was found to be a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of '' Maiaspondylus cantabrigiensis'' and in 2021 ''"Platypterygius" sachicarum'' was described by Cortés ''et al.'' as ''

Kyhytysuka sachicarum ''Kyhytysuka'' () is an extinct genus of ophthalmosaurian ichthyosaur from Early Cretaceous Colombia. The animal was previously assigned to the genus ''Platypterygius'', but given its own genus in 2021. ''Kyhytysuka'' was a mid-sized ophthal ...

''. It is argued that the inclusion of oldest species ''"P." hauthali'' requires reinvestigation, for it lacks a skull to attribute. Because of this, recent analyses on ichthyosaur classification neglect this species.

Accepted species

* ''Platypterygius platydactylus'' * ''Platypterygius americanus'' (=''Tenuirostria'') * ''Platypterygius australis'' (=''Longirostria'') * ''Platypterygius hercynicus''

Formerly assigned species

* '' Pervushovisaurus bannovkensis'' * '' Pervushovisaurus campylodon'' * '' Simbirskiasaurus birjukovi'' * '' Plutoniosaurus bedengensis'' * '' Maiaspondylus cantabrigiensis'' (

senior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

of ''Platypterygius ochevi'' ) * ''

'' (formerly ''Platypterygius sachicarum'' )

Classification

The following cladogram shows the internal relationships of ophthalmosaurian ichthyosaurs according to an analysis performed by Zverkov and Jacobs (2020) which shows that ''P. americanus'' is too distantly related compared to the other three species.

References

Bibliography

* * * *

External links

Dann's Dinosaurs

{{Portal bar, Paleontology, Cretaceous Ichthyosauromorph genera Early Cretaceous ichthyosaurs Late Cretaceous ichthyosaurs Hauterivian genus first appearances Barremian life Aptian life Albian life Cenomanian genus extinctions Cretaceous reptiles of Asia Cretaceous Russia Fossils of Russia Cretaceous reptiles of Australia Fossils of Australia Fossils of New Zealand Cretaceous reptiles of Europe Cretaceous France Fossils of France Cretaceous Germany Fossils of Germany Mesozoic Switzerland Fossils of Switzerland Cretaceous United Kingdom Fossils of England Cretaceous reptiles of North America Cretaceous Canada Fossils of Canada Cretaceous United States Fossils of the United States Early Cretaceous reptiles of South America Cretaceous Argentina Fossils of Argentina Cretaceous Chile Fossils of Chile Cretaceous Colombia Fossils of Colombia Altiplano Cundiboyacense Paja Formation Cretaceous Venezuela Fossils of Venezuela Fossil taxa described in 1922 Taxa named by Friedrich von Huene Ophthalmosauridae