| Dactylosaurus Temporal range: Early-Middle Triassic, | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | † Sauropterygia |
| Family: | † Pachypleurosauridae |
| Genus: | † Dactylosaurus Gürich, 1884 |
| Type species | |
| †Dactylosaurus gracilis Gürich, 1884 | |
| Synonyms | |
| |
Dactylosaurus is a genus of nothosaur in the family Pachypleurosauridae. Along with Anarosaurus , Dactylosaurus was one of the earliest known pachypleurosaurs to come from Europe. [1]
Dactylosaurus comes from the Greek daktulos (δακτυλος), "finger" and sauros (σαυρος), meaning "lizard" or "reptile."
Dactylosaurus was a small reptile measuring up to 50 cm (1.6 ft) long. [2] The nasal bones of Dactylosaurus meet and are broadly structured. [3] The upper temporal fenestra is large and kidney-shaped. [3] There are 17 cervical vertebrae [3] and the cervical ribs have anterior processes. [3] The maxillae of Dactylosaurus extended broadly up the side of the snout. [1]
The holotype specimen (MGUWR WR 3871s) of D. gracilis was only a partial skeleton, consisting of the anterior end alone. [1] Because it differed slightly from the fossils of D. gracilis, it was first thought to belong to the species D. schroederi, [1] which is now considered a junior synonym for juvenile D. gracilis. [3] Once this was established, the juvenile fossil, which was found before the adult fossils, became the holotype. The one limb that was found (a left forelimb), was noted to have a slimmer radius and ulna than Neusticosaurus , [1] a similar nothosaur from Europe. [1] D. gracilis is the smallest known species in its family, [1] which includes the much more recognized Keichousaurus , a nothosaur often remembered for its small size. [4] The original holotype of D. gracilis is considered a juvenile, [3] however the size of a nothosaur when its bones harden is used to show size, making the estimate as smallest member of its family still valid. [1]
Dactylosaurus lived in the Early and Middle Triassic period during the Late Olenekian and Anisian [3] faunal stage, of central Europe. [5]
In terms of geology, they are found: 1) in the uppermost Röt (uppermost Buntsandstein; Lower Triassic): e.g. Michałkowice (Siemianowice Śląskie) and Kamień Śląski, S Poland, [3] (the second location is not sure because Röt is not exposed there), 2) in the lowermost Muschelkalk (Middle Triassic), inter alia in the Gogolin Formation - Gogolin and its vicinity, S Poland. [5] [6]
In 2012, the new Röt site (~ 247 Ma; Lower Triassic; the latest Olenekian) with abundant disarticulated remains of Dactylosaurus was found in Gogolin. Presently, this in the only site where Dactylosaurus remains are accessible to collect. [7] [8] [9]
Sauropterygia is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the pliosaurs, developed a similar mechanism in their pelvis.
Nothosaurs were Triassic marine sauropterygian reptiles. They averaged about 3 metres (10 ft) in length, with a long body and tail. The feet were paddle-like, and are known to have been webbed in life, to help power the animal when swimming. The neck was quite long, and the head was elongated and flattened, and relatively small in relation to the body. The margins of the long jaws were equipped with numerous sharp outward-pointing teeth, indicating a diet of fish and squid.
Nothosaurus is an extinct genus of sauropterygian reptile from the Triassic period, approximately 240–210 million years ago, with fossils being distributed from North Africa and Europe to China. It is the best known member of the nothosaur order.
Pachypleurosauria is an extinct clade of primitive sauropterygian reptiles that vaguely resembled aquatic lizards, and were limited to the Triassic period. They were elongate animals, ranging in size from 0.2–1 metre (0.66–3.28 ft), with small heads, long necks, paddle-like limbs, and long, deep tails. The limb girdles are greatly reduced, so it is unlikely these animals could move about on land. The widely spaced peg-like teeth project at the front of the jaws, indicating that these animals fed on fish. In the species Prosantosaurus, it was observed that they fed on small fishes and crustaceans which they devoured entirely and that its teeth regrew after they broke off. This was the first observation of tooth replacement in a European pachypleurosaur, the only other discovery of such an event was made in China.
Ceresiosaurus is an extinct aquatic genus of lariosaurine nothosaurid sauropterygian known from the Middle Triassic of Monte San Giorgio, southern Switzerland and northern Italy. Ceresiosaurus, meaning "Lizard of Ceresio". The type species, Ceresiosaurus calcagnii, was named by Bernhard Peyer in 1931. C. calcagnii is known from both the Cava superiore and Cava inferiore beds of the Lower Meride Limestone at Monte San Giorgio, dating to the latest Anisian of the Middle Triassic. Rieppel (1998) suggested that the back then monospecific genus Ceresiosaurus, is a junior synonym of the better known Lariosaurus, yet he kept it type species as a separate species under the new combination L. calcagnii. In 2004, however, this synonymy was objected by Hänni who described and name a second species of Ceresiosaurus, C. lanzi - a separation supported by several other authors since. This species is known only from the stratigraphically younger Cassima beds of Monte San Giorgio, although also from the Lower Meride Limestone, dating to possibly the lowest Ladinian age. The species in a subtropical lagoonal environment with varying open marine influences, and alongside many related but smaller species of nothosaurids and pachypleurosaurids. Ceresiosaurus represents one of the largest vertebrate of up to 3 m (9.8 ft) snout-tail length from the very diversified paleoenvironment of the Middle Triassic Monte San Giorgio.
Keichousaurus (key-cho-saurus) is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the Triassic in the Triassic-Jurassic extinction event. The name derives from Kweichow in China where the first fossil specimen was discovered in 1957. They are among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors. Keichousaurus, and the pachypleurosaur family broadly, are sometimes classified within Nothosauroidea, but are otherwise listed as a separate, more primitive lineage within Sauropterygia.
Anarosaurus is an extinct genus of pachypleurosaurs that lived in the Middle Triassic period (Anisian) and has been found in the Jena Formation and the Karlstadt Formation of Germany and the Winterswijk Quarry of The Netherlands. Two species are known: A. pumilio and A. heterodontus. The holotype of A. pumilio was originally housed at the Institut und Museum fur Geologie und Palaontologie, Georg-August-Universitat, Gottingen, but can no longer be located today because it was lost or destroyed during World War II. Anarosaurus was a small reptile with an estimated body length of 50–60 cm (1.6–2.0 ft).
Rhizocorallium is an ichnogenus of burrow, the inclination of which is typically within 10° of the bedding planes of the sediment. These burrows can be very large, over a meter long in sediments that show good preservation, e.g. Jurassic rocks of the Yorkshire Coast, but the width is usually only up to 2 cm, restricted by the size of the organisms producing it. It is thought that they represent fodinichnia as the animal scoured the sediment for food.
Cymatosaurus is an extinct genus of pistosauroid or nothosauriform sauropterygian. It is known to have been alive from the Early Triassic to the Middle Triassic period of Germany and they seem to originate from the Netherlands. It was a small reptile measuring 1–1.2 metres (3.3–3.9 ft) long.
Serpianosaurus is an extinct genus of pachypleurosaurs known from the Middle Triassic deposits of Switzerland and Germany. It was a small reptile, with the type specimen of S. mirigiolensis measuring 75 cm (2.46 ft) long.
Simosaurus is an extinct genus of marine reptile within the superorder Sauropterygia from the Middle Triassic of central Europe. Fossils have been found in deposits in France and Germany that are roughly 230 million years old. It is usually classified as a nothosaur, but has also been considered a pachypleurosaur or a more primitive form of sauropterygian.
Sinosaurosphargis is an extinct genus of basal marine saurosphargid reptile known from the Middle Triassic Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a single species, Sinosaurosphargis yunguiensis.
Corosaurus is an extinct genus of pistosauroid known from Wyoming of the United States. The holotype measured about 1.65 m (5.4 ft) long, while larger specimens would have belonged to individuals measuring more than 4 m (13 ft) long.
Hanosaurus is an extinct genus of marine reptiles that existed during the Triassic period in what is now China. The type species is Hanosaurus hupehensis. It was a small animal, with specimens measuring 79.4 cm (31.3 in) long in total body length, which likely fed on soft-bodied prey.
Gogolin Formation – Triassic geologic formation, hitherto named the Gogolin Beds, is the lowermost lithostratigraphical unit of the Lower Muschelkalk in the Silesian-Cracow Upland, underlain by the Upper Buntsandstein carbonates and overlain by the Górażdże Formation carbonates.
Eohupehsuchus is a genus of extinct aquatic diapsid from the Upper Spathian of Hubei Province, located in Central China. The genus is monotypic and belongs to the order Hupehsuchia, whose members are characterized by toothless beak-like snouts, a row of dermal plates along their backs, and aquatic adaptations including paddle-shaped limbs and fusiform bodies with pachyostotic ribs.
Majiashanosaurus is an extinct genus of pachypleurosaur or alternatively a basal eosauropterygian known from the Early Triassic of Anhui Province, eastern China. It contains a single species, Majiashanosaurus discocoracoidis.
Saurosphargidae is an extinct family of marine reptiles known from the early Middle Triassic of Europe and China.
Panzhousaurus is an extinct genus of pachypleurosaur from the Middle Triassic of China. The type species is P. rotundirostris. The preserved portion of the holotype measures 36 cm (14 in) long, and its total body length may have been less than 50 cm (20 in).
This list of fossil reptiles described in 2014 is a list of new taxa of fossil reptiles that were described during the year 2014, as well as other significant discoveries and events related to reptile paleontology that occurred in 2014.
