Hyporhina Temporal range: Late Eocene − Middle Oligocene, 40–30 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Family:	Rhineuridae
Genus:	†Hyporhina Baur, 1893
Species
†H. antiqua Baur, 1893 (type) †H. galbreathi Taylor, 1951

Hyporhina is an extinct genus of amphisbaenians or worm lizards that lived from the Late Eocene to the Middle Oligocene (approximately 40 to 30 million years ago) in what is now the western United States.

It currently includes two species, both from the White River Formation in eastern Wyoming and northeastern Colorado:

• Hyporhina antiqua — the type species.
• Hyporhina galbreathi
• Hyporhina tertia — a third species named in 1972, and later synonymized with Hyporhina galbreathi.

Paleontologist Georg Baur named the genus Hyporhina in 1893, making it one of the first prehistoric amphisbaenians to be described. Baur placed it in its own family, Hyporhinidae, because it possessed eye sockets that are enclosed at the back by postorbital bars, a feature that living amphisbaenians lack.

However, more recent studies have placed it within Rhineuridae, a family that includes the living Rhineura floridana from Florida, and many more extinct species from the western United States that were named after 1893 and have postorbital bars. Hyporhina differs from other rhineurids in having a steep angle to its snout.^[1]

• White River Formation prehistoric fauna

v t e Extinct squamate genera
Kingdom: Animalia Phylum: Chordata Class: Reptilia Superorder: Lepidosauria
Iguania Acrodonta Anqingosaurus Barbaturex Bharatagama Gueragama Xianglong Agamidae Indiagama Suratagama Pleurodonta / Iguanoidea Anolbanolis Suzanniwana Uquiasaurus Xihaina Corytophanidae Aciprion? Babibasiliscus Geiseltaliellus †Gobiguania Anchaurosaurus Ctenomastax Igua Isodontosaurus Polrussia Saichangurvel Temujinia Zapsosaurus Iguanidae Afairiguana Polychrotidae Armandisaurus Lapitiguana Pariguana Pristiguana Pumilia Phrynosomatidae Desertiguana Other extinct iguanians Brasiliguana Hoyalacerta? Huehuecuetzpalli? Swainiguanoides †Arretosauridae Arretosaurus Dornosaurus Ergiliinsaurus Khaichinguana †Priscagamidae Heterodontagama Mimeosaurus Phrynosomimus Pleurodontagama? Priscagama
†Polyglyphanodontia / Borioteiioidea Chamopsiidae Chamops Gerontoseps Glyptogenys Harmodontosaurus Haptosphenus Leptochamops Meniscognathus Pelsochamops Socognathus Stypodontosaurus Trippenaculus Gilmoreteiidae / "macrocephalosaurines" Gilmoreteius Kuwajimalla Yechilacerta "Polyglyphanodontines" Bicuspidon Cherminsaurus Darchansaurus Distortodon Erdenetesaurus Polyglyphanodon Sineoamphisbaena? Other polyglyphanodontians Adamisaurus Funiusaurus Gobinatus Obamadon Olindalacerta? Paleochelco? Peneteius Tchingisaurus Tianyusaurus Tijubina? Tripennaculus
Stem Scincogekkonomorpha Scincogekkonomorpha Ardeosaurus? Bavarisaurus? Eichstaettisaurus? Jucaraseps Liushusaurus? Pedrerasaurus Scandensia? Yabeinosaurus? Scleroglossa Gekkonomorpha Norellius Gekkota Cadurcogekko Cretaceogekko Gobekko Hoburogekko Yanatarogecko Stem Autarchoglossa (Evansauria) Parmeosaurus Tepexisaurus Tijubina? †Bainguidae? Bainguis? Eoxanta Globaura Myrmecodaptria
Scincomorpha Cordyloidea Eocordyla Ornatocephalus Sakurasaurus Lacertoidea Cnodontosaurus Paracontogenys Purbicella †Polyglyphanodontia? Amphisbaenia Oligodontosaurus Todrasaurus Amphisbaenidae Listromycter Lophocranion Bipedidae Anniealexandria Blanidae Blanosaurus Cuvieribaena Louisamphisbaena †Chthonophidae Chthonophis Rhineuridae Archaerhineura Dyticonastis Hadrorhineura Hyporhina Jepsibaena Macrorhineura Ototriton Plesiorhineura Protorhineura Spathorhynchus †Polyodontobaenidae Polyodontobaena †Contogeniidae Contogenys Palaeoscincosaurus Utahgenys Lacertidae Amblyolacerta Camptognathosaurus? Dormaalisaurus Dracaenosaurus Escampcerta Gracilicerta Ligerosaurus Maioricalacerta Mediolacerta Plesiolacerta Pseudeumeces Pseudolacerta Quercycerta Teiidae Brevisaurus? Meyasaurus? Ptilotodon †Barbatteiidae Barbatteius Oardasaurus Xantusiidae Catactegenys Palepidophyma Palaeoxantusia Scincoidea Retinosaurus Scincoideus Slavoia Scincidae Axonoscincus Orthoscincus Pyrenasaurus? Other scincomorphs Apsgnathus Calanguban Chromatogenys Dakotaseps Kleskunsaurus Lonchisaurus Monocnemodon Pachygenys Saurillodon Saurillus Sciroseps Webbsaurus †Paramacellodidae Atokasaurus? Becklesius Mimobecklesisaurus Paramacellodus Parasaurillus? Pseudosaurillus? Sharovisaurus
Anguimorpha Basal anguimorphs Chometokadmon Eolacerta Paramacellodus Paravaranus? Yabeinosaurus? †Mosasauroidea? †Aigialosauridae †Mosasauridae Neoanguimorpha Carusioidea Carusia Xenosauridae Entomophontes Exostinus Restes Anguidae Odaxosaurus Anguinae Headonhillia Helvetisaurus Ophisauriscus Ragesaurus Diploglossinae Apodosauriscus Eodiploglossus Gerrhonotinae Paragerrhonotus Parophisaurus †Glyptosaurinae Arpadosaurus Melanosaurus Gaultia Glyptosaurus Helodermoides Odaxosaurus Paraglyptosaurus Paraplacosauriops Peltosaurus Placosaurus Proglyptosaurus Proxestops Xestops Paleoanguimorpha Basal varanoids / platynotans Aiolosaurus Colpodontosaurus Dorsetisaurus Eosaniwa Palaeovaranus Parasaniwa Parviderma Proplatynotia Saniwides Telmasaurus Shinisauria? Bahndwivici Dalinghosaurus Merkurosaurus Provaranosaurus Goannasauria Basal Goannasaurians Asprosaurus Chianghsia Estesia Eurheloderma Gobiderma Lowesaurus Morohasaurus Palaeosaniwa Paraderma Primaderma Varanoidea Lanthanotidae Cherminotus Varanidae Ovoo Saniwa Archaeovaranus Other platynotans / varanoids Arcanosaurus? Cemeterius Dryadissector
Ophidia Coniophis Diablophis Dinilysia? Eophis Lapparentophis Najash? Parviraptor Portugalophis Tetrapodophis See Serpentes (snakes)
Indeterminate squamates Costasaurus Lamiasaura Oculudentavis? Schillerosaurus