(q) |
No edit summary Tag: sourceedit |
||
| (7 intermediate revisions by 2 users not shown) | |||
| Line 18: | Line 18: | ||
}} |
}} |
||
| − | '''Plesiosaurs''' |
+ | '''Plesiosaurs'''were a diverse and highly successful group of marine reptiles that made up the order '''Plesiosauria'''. They were entirely or almost entirely aquatic, and thrived throughout the Jurassic and Cretaceous periods. Plesiosaurs became extinct during the Cretaceous-Paleogene extinction event, which was also responsible for the extinction of non-avian dinosaurs, [[pterosaur]]s, and most marine reptiles. |
| − | The order Plesiosauria was comprised of two superfamilies, Plesiosauroidea and [[Pliosaur |
+ | The order Plesiosauria was comprised of two superfamilies, Plesiosauroidea and [[Pliosaur]]oidea. |
| + | |||
| + | == Taxonomy == |
||
| + | |||
| + | Order '''Plesiosauria''' |
||
| + | *Superfamily '''Plesiosauroidea''' |
||
| + | **Family [[Cryptoclididae]] |
||
| + | **Family [[Elasmosauridae]] |
||
| + | **Family [[Muraenosauridae]] |
||
| + | **Family [[Plesiosauridae]] |
||
| + | *Superfamily [[Pliosauroidea]] |
||
| + | **Family [[Pliosauridae]] |
||
| + | **Family [[Rhomaleosauridae]] |
||
| + | |||
| + | == Characteristics == |
||
| + | [[File:Cryptoclidus_fossil_1.jpg|thumb|Mounted fossil of ''Cryptoclidus sp.''.]] |
||
| + | Plesiosaurs were medium to large-sized marine reptiles. The smallest, around 1.8 meters (6 feet) long and 70 kilograms in weight, belong to the dubious genus "''[[Plesiosaurus]]''". The largest plesiosaur species are the elasmosaurid ''[[Mauisaurus]] haasti'' and the pliosaurid genus ''[[Pliosaurus]] macromerus'', which both may have weighed between 20 and 30 tons and attained 20 and 11 metres long, respectively. ''[[Elasmosaurus|Elasmosaurus platyurus]]'' was also very large, growing to 14 meters long and possibly exceeding 12 tons. |
||
| + | |||
| + | Plesiosaurs possessed broad, sometimes slightly flattened bodies with oar-shaped flippers. As with all vertebrates, each flipper possessed five fingers. Both plesiosauroids and pliosauroids had relatively short tails that appear to have been used as rudders rather than for propulsion. Unlike [[mosasaur]]s, plesiosaurs probably relied solely on their flippers for propulsion. |
||
| + | |||
| + | The necks of pliosauroids were comparatively short and heavily muscled, while plesiosauroids' necks were both relatively and absolutely longer. In plesiosaurs such as ''Elasmosaurus spp.'' the neck may have been more than 50% of the animal's total length and contained over 70 cervical vertebrae. Contrary to popular belief, the necks of plesiosauroids would have been relatively stiff and not held above the body like the neck of a sauropod. |
||
| + | |||
| + | ==See also== |
||
| + | *[[Pliosaur]] |
||
| + | *[[Nothosaur]] |
||
| + | *[[Ichthyosaur]] |
||
| + | *[[Mosasaur]] |
||
| + | [[Category:Extinct fauna]] |
||
| + | [[Category:Marine reptiles]] |
||
Revision as of 16:06, 24 February 2015
| Plesiosaurs | |
|---|---|
 | |
| Physical description | |
| Lifespan | Unknown |
| Average Size | 1.8-20 m |
| Average weight | 75 kg-30 t |
| Diet | Carnivorous |
| Conservational Status | |
| Status | Extinct |
| IUCN status | Fossil |
| Scientific classification | |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Reptilia |
| Order | Plesiosauria |
| Family | 6; see text |
| Genus | Approximately 36 |
Plesiosaurswere a diverse and highly successful group of marine reptiles that made up the order Plesiosauria. They were entirely or almost entirely aquatic, and thrived throughout the Jurassic and Cretaceous periods. Plesiosaurs became extinct during the Cretaceous-Paleogene extinction event, which was also responsible for the extinction of non-avian dinosaurs, pterosaurs, and most marine reptiles.
The order Plesiosauria was comprised of two superfamilies, Plesiosauroidea and Pliosauroidea.
Taxonomy
Order Plesiosauria
- Superfamily Plesiosauroidea
- Family Cryptoclididae
- Family Elasmosauridae
- Family Muraenosauridae
- Family Plesiosauridae
- Superfamily Pliosauroidea
- Family Pliosauridae
- Family Rhomaleosauridae
Characteristics
Mounted fossil of Cryptoclidus sp..
Plesiosaurs were medium to large-sized marine reptiles. The smallest, around 1.8 meters (6 feet) long and 70 kilograms in weight, belong to the dubious genus "Plesiosaurus". The largest plesiosaur species are the elasmosaurid Mauisaurus haasti and the pliosaurid genus Pliosaurus macromerus, which both may have weighed between 20 and 30 tons and attained 20 and 11 metres long, respectively. Elasmosaurus platyurus was also very large, growing to 14 meters long and possibly exceeding 12 tons.
Plesiosaurs possessed broad, sometimes slightly flattened bodies with oar-shaped flippers. As with all vertebrates, each flipper possessed five fingers. Both plesiosauroids and pliosauroids had relatively short tails that appear to have been used as rudders rather than for propulsion. Unlike mosasaurs, plesiosaurs probably relied solely on their flippers for propulsion.
The necks of pliosauroids were comparatively short and heavily muscled, while plesiosauroids' necks were both relatively and absolutely longer. In plesiosaurs such as Elasmosaurus spp. the neck may have been more than 50% of the animal's total length and contained over 70 cervical vertebrae. Contrary to popular belief, the necks of plesiosauroids would have been relatively stiff and not held above the body like the neck of a sauropod.