| Rhineura Temporal range: Miocene – Recent | |
|---|---|
 | |
| Florida worm lizard (Rhineura floridana) | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Family: | Rhineuridae |
| Genus: | Rhineura Cope, 1861 |
| Species | |
Rhineura is a genus of worm lizard endemic to North America. The genus has only one extant species [1] [2] but more are known from fossil record. [3] They are also known as the North American worm lizards. [2]
This genus has a fossil record dating back to at least the Early Miocene, [4] although if Protorhineura hatcherii is classified as belonging to Rhineura (as it has in the past), the record extends back well into the Oligocene.
While the extant Florida worm lizard is largely restricted to northern Florida, the genus was far more widespread in the past, with the extinct R. marslandensis and R. sepultura known from the Miocene of Nebraska and South Dakota, respectively. [5] [6]
Amphisbaenia is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As many species have a pink body and scales arranged in rings, they have a superficial resemblance to earthworms. While the genus Bipes retains forelimbs, all other genera are limbless. Phylogenetic studies suggest that they are nested within Lacertoidea, closely related to the lizard family Lacertidae. Amphisbaenians are widely distributed, occurring in North America, Europe, Africa, South America, Western Asia and the Caribbean. Most species are less than 6 inches (15 cm) long.
Pseudopus is a genus of anguid lizards that are native to Eurasia. One extant species remains, the sheltopusik, with four fossil species. They are the most robust members of subfamily Anguinae. The oldest fossils of the group date to the Early Miocene, but there are possible Oligocene records.
The Molidae comprise the family of the molas or ocean sunfishes, unusual fish whose bodies come to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance. They are also the largest of the ray-finned bony fish, with the southern sunfish, Mola alexandrini, recorded at 4.6 m (15 ft) in length and 2,744 kg (6,049 lb) in weight.
Miracinonyx is an extinct genus of felids belonging to the subfamily Felinae that was endemic to North America from the Pleistocene epoch and morphologically similar to the modern cheetah, although its apparent similar ecological niches have been considered questionable due to anatomical morphologies of the former that would have limited the ability to act as a specialized pursuit predator. The genus was originally known from fragments of skeletons, but nearly complete skeletons have been recovered from Natural Trap Cave in northern Wyoming.
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.
Phlaocyon is an extinct genus of the Borophaginae subfamily of canids native to North America. It lives from the Early Oligocene to the Early Miocene epoch 33.3–16.3 Mya, existing for approximately 17.3 million years. It is closely related to Cynarctoides.
Rhineura floridana, known commonly as the Florida worm lizard, graveyard snake, or thunderworm, is a species of amphisbaenian in the family Rhineuridae. The species is the only extant member of the genus Rhineura, and is found primarily in Florida but has been recorded in Lanier County, Georgia. There are no subspecies that are recognized as being valid.
Chachalacas are galliform birds from the genus Ortalis. These birds are found in wooded habitats in the far southern United States (Texas), Mexico, and Central and South America. They are social, can be very noisy and often remain fairly common even near humans, as their relatively small size makes them less desirable to hunters than their larger relatives. As agricultural pests, they have a ravenous appetite for tomatoes, melons, beans, and radishes and can ravage a small garden in short order. They travel in packs of six to twelve. Their nests are made of sticks, twigs, leaves, or moss and are generally frail, flat structures only a few feet above the ground. During April, they lay from three to five buffy white eggs, the shell of which is very rough and hard. They somewhat resemble the guans, and the two have commonly been placed in a subfamily together, though the chachalacas are probably closer to the curassows.
Rhineuridae is a family of amphisbaenians that includes one living genus and species, Rhineura floridana, as well as many extinct species belonging to both Rhineura and several extinct genera. The living R. floridana is found only in Georgia and Florida, but extinct species ranged across North America, some occurring as far west as Oregon. The family has a fossil record stretching back 60 million years to the Paleocene and was most diverse in the continental interior during the Eocene and Oligocene.
Parictis is an extinct arctoid belonging to the family Subparictidae.
The Alethinophidia are an infraorder of snakes that includes all snakes other than blind snakes and thread snakes. Snakes have long been grouped into families within Alethinophidia based on their morphology, especially that of their teeth. More modern phylogenetic hypotheses using genetic data support the recognition of 19 extant families, although the taxonomy of alethinophidian snakes has long been debated, and ultimately the decision whether to assign a particular clade to a particular Linnaean rank is arbitrary.
Nannippus is an extinct genus of three-toed horse endemic to North America during the Miocene through Pleistocene, about 13.3—1.8 million years ago (Mya), living around 11.5 million years. This ancient species of three-toed horse grew up to 3.5 feet and weighed between 165 pounds to 199 pounds, which was around the same size as a domestic sheep.
Hesperotestudo is an extinct genus of tortoise native to North and Central America from the Early Miocene to the Late Pleistocene. Species of Hesperotestudo varied widely in size, with a large undescribed specimen from the Late Pleistocene of El Salvador reaching
Herpetotherium is an extinct genus of metatherian mammal, belonging to the possibly paraphyletic family Herpetotheriidae. Native to North America from the Eocene to Early Miocene, fossils have been found in California, Oregon, Texas, Florida, Montana, Wyoming, Colorado, North and South Dakota, Nebraska, and Saskatchewan. The oldest species, H. knighti, is dated to around 50.3 mya, and the most recent, an unnamed species, may be as recent as 15.97 mya. A morphological analysis of marsupials and basal metatherians conducted in 2007 found Herpetotherium to be the sister group to extant marsupials. It is the youngest known metatherian from North America until the migration of the Virginia opossum from South America within the last 2 million years.
Nimravides is a genus of extinct saber-toothed cats that lived in North America during the Late Miocene, between 10.3 and 5.332 Ma. Despite its scientific name, Nimravides does not belong to the Nimravidae, but is a true cat belonging to the family Felidae.
Nordenosaurus is an extinct genus of crocodilian. When first named in 1973 the genus was thought to be a squamate and was assigned to the family Xenosauridae. A single frontal bone was found from the Norden Bridge locality of the lower Valentine Formation in Brown County, Nebraska, thought to date back to the late Miocene. The size of the bone was initially taken as evidence that it was a giant xenosaurid. The specific name of the type species, N. magnus, alludes to its extremely large size in comparison to other xenosaurids known at the time. In 1982, paleontologist Jacques Gauthier reinterpreted Nordenosaurus as a small crocodilian rather than a giant xenosaurid. The frontal bone is hour-glass shaped and covered in deep pits, unlike those of any lizard but similar to the frontals of most crocodilians.
Dyticonastis is an extinct genus of amphisbaenians, or worm lizards, that includes a single species, Dyticonastis rensbergeri, that lived during the late Oligocene and early Miocene in what is now Oregon. Fossils of the species come from the John Day Formation. It belongs to Rhineuridae, a family that includes many other extinct North American amphisbaenians but only one living species, Rhineura floridana, from Florida. Dyticonastis rensbergeri occurs the farthest west of all rhineurid species. Like all rhineurids, Dyticonastis has a shovel-like snout adapted for burrowing underground, but it differs from most other members of the group in having a relatively shallow angle to its snout wedge and in having a widened snout tip. The only other rhineurids that share these features are species of the genus Spathorhynchus, which lived from the Middle Eocene to the Early Oligocene in what is now Wyoming. A 2007, phylogenetic analysis of amphisbaenians found that Dyticonastis and Spathorhynchus are each other's closest relatives, suggesting that both taxa may have evolved through vicariant speciation; the growth of the Rocky Mountains during the earliest stages of the Laramide orogeny in the early Paleogene would have separated North American rhineurids into eastern and western populations, with the western population producing Dyticonastis and Spathorhynchus.
Macrorhineura is an extinct genus of rhineurid amphisbaenian or worm lizard, including the type and only species Macrorhineura skinneri, named in 1970 on the basis of the front half of a skull from the Early Miocene Sharps Formation in Wounded Knee, South Dakota. Although the skull is incomplete, features such as a pointed, shovel-shaped snout indicate that it belongs to the family Rhineuridae. Within Rhineuridae, Macrorhineura is most closely related to Ototriton and Hyporhina, two genera from the Eocene and Oligocene of Colorado and Wyoming, based on the shared feature of equally sized dentary teeth in the lower jaw. Together they form a clade or evolutionary grouping of mid-continental rhineurids, which became isolated from a more western clade of rhineurids that includes Dyticonastis and Spathorhynchus. Rhineurids were relatively common across much of North America during the Paleogene, but their range contracted in the Neogene as the climate became colder, leaving only one living species in Florida, Rhineura floridana. The presence of Macrorhineura in the Miocene shows that mid-continental rhineurids persisted into the Neogene, although by this time their distribution range was already shrinking.
The Ash Hollow Formation of the Ogallala Group is a geological formation found in Nebraska and South Dakota. It preserves fossils dating back to the Neogene period. It was named after Ash Hollow, Nebraska and can be seen in Ash Hollow State Historical Park. Ashfall Fossil Beds State Historical Park is within this formation.
The Valentine Formation is a geologic unit formation or member within the Ogallala unit in northcentral Nebraska near the South Dakota border. It preserves fossils dating to the Miocene epoch of the Neogene period and is particularly noted for Canid fossils. This unit consists of loosely-consolidated sandstone that crumbles easily. These sands carry the water of the Ogallala Aquifer and is the source of much of the water in the Niobrara River. A particular feature of the Valentine is lenticular beds of green-gray opaline sandstone that can be identified in other states, including South Dakota, Nebraska, Kansas, and Colorado. Although three mammalian fauna stages can be mapped throughout the range of the Ogallala, no beddings of the Ogallala are mappable and all attempts of formally applying the Valentine name to any mappable lithology beyond the type location have been abandoned. Even so, opaline sandstone has been used to refer to this green-gray opalized conglomerate sandstone that is widely found in the lower Ogallala Formation.