| Glyptosaurinae Temporal range: | |
|---|---|
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| Fossil of the glyptosaurine Helodermoides tuberculatus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Family: | Anguidae |
| Subfamily: | † Glyptosaurinae Marsh, 1872 |
| Subgroups | |
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Glyptosaurinae is an extinct subfamily of anguid lizards that lived in the Northern Hemisphere during the Late Cretaceous and the Paleogene.
Glyptosaurines are known primarily from their osteoderms, scale-like pieces of bone that are embedded in the skin and cover much of their bodies. The shape and extent of the osteoderms in glyptosaurines are similar to those seen in an unrelated group of lizards called Monstersauria, which includes the living Gila monster and beaded lizard. [1] The osteoderms of glyptosaurines are unusually complex, consisting of four distinct layers of bony tissue. These tissues may have derived from both the dermis (the lower layer of the skin) and the epidermis (the outer layer of the skin) during their development in the embryo. The tissue forming the outermost layer of glyptosaurine osteoderms is similar to tooth enamel and has even been given its own name, osteodermine. [2]
Glyptosaurines have been split into the subgroups Melanosaurini and Glyptosaurini, although recent phylogenetic analyses show that Melanosaurini in its traditional sense is paraphyletic, representing an evolutionary grade of glytosaurines more basal ("primitive") than Glyptosaurini. Below is a cladogram from Conrad and Norell (2008) showing the interrelationships of glyptosaurines and their relationship to other anguid lizards: [1]
| Anguimorpha |
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The earliest known Glyptosaurines like Odaxosaurus are known from the Late Cretaceous (Campanian) of North America. They arrived in Europe at the beginning of the Eocene (Ypresian). Only a single species, Stenoplacosaurus mongoliensis dating to the Mid-Eocene, is known from Asia. Glyptosaurines declined after the Mid-Eocene, become extinct in Europe by the end of the period as part of the "Grande Coupure". [3] The youngest known remains of glyptosaurines is Peltosaurus granulosus from the Monroe Creek and upper Sharps formations of Sharps Corner, South Dakota, dating to the mid Oligocene, between 27.4 and 26.4 million years ago. [4] The extinction of glyptosaurines was likely due to a cooling climate during the Oligocene. [5]
Kogaionidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of Europe. Having started as island endemics on Hateg Island during the Upper Cretaceous, where they were in fact the dominant mammal group and diverged into rather unique ecological niches, they expanded across Europe in the Paleocene, where they briefly became a major component of its mammal fauna before their extinction. They are considered to be basal members of Cimolodonta.
Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold in the skin of most taxa. The group is divided into two living subfamilies, the legless Anguinae, which contains slow worms and glass lizards, among others, found across the Northern Hemisphere, and Gerrhonotinae, which contains the alligator lizards, native to North and Central America. The family Diploglossidae was also formerly included. The family contains about 87 species in 8 genera.
Xenosauridae is a family of anguimorph lizards whose only living representative is the genus Xenosaurus, which is native to Central America. Xenosauridae also includes the extinct genera Exostinus and Restes. Also known as knob-scaled lizards, they have rounded, bumpy scales and osteoderms. Most living species prefer humid, rocky habitats, although they are widespread within their native regions, with some inhabiting semi-arid scrub environments. They are carnivorous or insectivorous, and give birth to live young.
Heloderma is a genus of toxicoferan lizards that contains five species, all of which are venomous. It is the only extant genus of the family Helodermatidae.
Peltosaurus is an extinct genus of anguid lizard from North America that lived from the Eocene to the Oligocene. Peltosaurus belongs to the anguid subfamily Glyptosaurinae. The type species Peltosaurus granulosus was named in 1873 by American paleontologist Edward Drinker Cope. Many additional species have been named, but most have been reassigned to different genera. For example, Peltosaurus piger, named in 1928, was reclassified as Odaxosaurus piger, and P. jepseni, named in 1942 from the Paleocene of Wyoming, but was later reclassified as Proxestops jepseni. In 1955 a new species, Peltosaurus macrodon, was named from the Eocene of California. Lizard bones from the Late Miocene of Nebraska were attributed to a new species of Peltosaurus called P. minimus in 1976, extending the fossil range of Peltosaurus and Glyptosaurinae into the Neogene. However, these bones were later referred to a genus of skinks called Eumeces, meaning that the fossil range of Peltosaurus and Glyptosaurinae does not go beyond the Paleogene.
Palaeeudyptes klekowskii is an extinct species of the penguin genus Palaeeudyptes. It was previously thought to have been approximately the size of its congener Palaeeudyptes antarcticus, somewhat larger than the modern emperor penguin, but a 2014 study showed it was in fact almost twice as tall, earning it the nickname “Mega Penguin”. Its maximum height is estimated to be up to 2 meters (6.6 ft) and maximum body mass up to 116 kg (256 lb). Knowledge of it comes from an extensive collection of fossil bones from the Late Eocene of the La Meseta Formation on Seymour Island, Antarctica. P. klekowskii was at first not recognized as a distinct species, and despite the coexistence of two so closely related species of similar size as Palaeeudyptes gunnari and P. klekowskii seeming somewhat improbable, the amount of fossil material suggests that the two species are indeed diagnosably different.
Tethysaurus is an extinct genus of tethysaurine mosasauroid from the Early Turonian period. The only species is Tethysaurus nopcsai.
Pipoidea are a clade of frogs, that contains the most recent common ancestor of living Pipidae and Rhinophrynidae as well as all its descendants. It is broadly equivalent to Xenoanura.
Saniwa is an extinct genus of varanid lizard that lived during the Eocene epoch. It is known from well-preserved fossils found in the Bridger and Green River Formations of Wyoming, United States. The type species S. ensidens was described in 1870 as the first fossil lizard known from North America. A second species, S.orsmaelensis, is recognised from remains found in Europe. It is a close relative of Varanus, the genus that includes monitor lizards.
Helodermoides is an extinct genus of anguid lizards from the Oligocene of North America. The genus is monotypic, including only the species Helodermoides tuberculatus. Helodermoides belongs to an extinct subfamily of anguids called Glyptosaurinae. In addition to many fragmentary bones, several complete skeletons of Helodermoides are known. Like other glyptosaurines, Helodermoides was covered in small scale-like bones called osteoderms. The osteoderms covering its skull are hexagonal, tightly interlocking, raised, and rounded.
Myrmecodaptria is an extinct genus of scleroglossan lizard from the Late Cretaceous Djadokhta Formation in Ukhaa Tolgod, Mongolia. The type and only species, Myrmecodaptria microphagosa, was named in 2000 by paleontologists Gao Keqin and Mark Norell. Myrmecodaptria is known from a single holotype skull and lower jaws. It is distinguished from all other lizards by its extremely elongated skull. The eyes are placed close to the snout, which is short and rounded. The top of the skull is covered in bony knobs called osteoderms. The parietal bone at the back of the skull is elongated and about as long as the frontal bones, which are the usually the longest bones along the top of the skull in lizards. The squamosal bone at the back of the skull reaches forward to connect with the jugal bone behind the eye, forming a thin arch between the temporal fenestrae. Myrmecodaptria also has fewer and more widely spaced teeth in its jaws than do most other lizards.
The Monroe Creek Formation is a geologic formation in South Dakota. It preserves fossils dating back to the Paleogene period.
The Sharps Formation is a geologic formation in South Dakota. It preserves fossils dating back to the Paleogene.
Osteoderms are dermal bone structures that support the upper layer of skin and serve as protection against the elements in a large variety of extinct and extant organisms, especially reptiles. This structure is commonly called "dermal armor" and serves to protect the organism, while also helping with temperature regulation. Osteoderms represent hard tissue components of the integument, making them easy to identify in fossil examination. This dermal armor is found prominently in many lizards. Some early amphibians have this armor, but it is lost in modern species with the exception a ventral plate, called the gastralia.
Oardasaurus is an extinct genus of lizard from the latest Cretaceous of Romania. It is a member of the Barbatteiidae, a group of lizards closely related to the Teiidae. At 20 centimetres (7.9 in) in length, it was much smaller than the only other named member of the Barbatteiidae, Barbatteius, which lived slightly later. Like Barbatteius, Oardasaurus can be identified by the presence of a crust of bone deposits, or osteoderms, on the roof of its skull; it differs from Barbatteius in the pattern of the sculpturing on this crust. Both Oardasaurus and Barbatteius lived in the isolated island ecosystem of Hațeg Island, having rapidly diversified into various generalist predators of small prey after their arrival on the island during the Early Cretaceous. They went extinct in the Cretaceous–Paleogene extinction event.
Diploglossa is a clade of neoanguimorphs represented by the families Xenosauridae, Diploglossidae, Anniellidae and Anguidae, the latter three placed in the superfamily Anguioidea. In the past the Chinese crocodile lizard was classified as a xenosaurid; current molecular work has shown evidence the species related to varanoids in the clade Paleoanguimorpha.
Stenoplacosaurus is an extinct genus of glyptosaurine anguid lizards from the Eocene of Inner Mongolia, China. The genus is monotypic, containing only the species Stenoplacosaurus mongoliensis.
Paraplacosauriops is an extinct genus of anguid lizards from the middle Eocene of France.
Robert Michael "Bob" Sullivan is a vertebrate paleontologist, noted for his work on fossil lizards and dinosaurs.
Geoscelionidae is a family of wasps in the superfamily Platygastroidea. It contains three extant species in two genera, native to South America and Africa, and several other genera known from fossils. It was originally erected as the tribe Geoscelionini within Scelionidae. It was raised to a full family in 2021.
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