Polyglyphanodontia, also known as the Borioteiioidea, is an extinct

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s. Polyglyphanodontians were the dominant group of lizards in North America and Asia during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent 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 ''cre ...

Chronology and distribution

Most polyglyphanodontians are Late Cretaceous in age, with the highest diversity in the group being known from East Asia. The oldest polyglyphanodontian, '' Kuwajimalla kagaensis'', is known from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

Kuwajima Formation of

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. The majority of known members of the group inhabited

Laurasia Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pa ...

; the group also included

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

n taxa '' Bicuspidon hogreli'' from the

Kem Kem Beds The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

, '' Cryptobicuspidon pachysymphysealis'' from the Quiricó Formation of

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

and '' Calanguban alamoi'' from the

Crato Formation The Crato Formation is a geologic formation (stratigraphy), formation of Early Cretaceous (Aptian) age in northeastern Brazil's Araripe Basin. It is an important Lagerstätten, Lagerstätte (undisturbed fossil accumulation) for palaeontology, pa ...

of Brazil,, while Early Cretaceous

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

n taxon '' Tijubina'', and possibly also '' Olindalacerta'', might also fall within Polyglyphanodontia or be closely allied to the group. The group became extinct during the end-Cretaceous extinction event, the only major terrestrial squamate group to do so.

Ecology

Polyglyphanodontians were morphologically diverse. Chamopsiids, including '' Chamops'', from North America have tricuspid teeth, and were generally small in size. Members of the family Polyglyphanodontidae primarily known from Europe and North America (including '' Polyglyphanodon'', '' Paraglyphanodon'', '' Dicodon'' and '' Bicuspidon'') have large teeth that are transversely orientated, and were likely herbivorous as well as possibly ominivorous. The family Gilmoreteiidae have iguana-like teeth, with some polyglyphanodontians known from Asia having conical teeth. Some gilmoreteiids developed a complete lower temporal bar similar to that found in the

tuatara The tuatara (''Sphenodon punctatus'') is a species of reptile endemic to New Zealand. Despite its close resemblance to lizards, it is actually the only extant member of a distinct lineage, the previously highly diverse order Rhynchocephal ...

, but is otherwise unheard of in lizards.

Classification

The classification of Polyglyphanodontia is contentious. They have been considered to be either most closely related to Teiioidea, or to

Iguania Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed ...

, with both positions having been supported in recent studies. Cladogram after Xida, Niu and Evans, 2023.

References

{{Taxonbar, from=Q864131 Scincogekkonomorpha Taxa described in 2000 Early Cretaceous first appearances Late Cretaceous extinctions