Search results
Results from the WOW.Com Content Network
Sauropterygians were a diverse group of aquatic reptiles adapted for flipper-based aquatic locomotion. This group included the plesiosaurs, nothosaurs, and placodonts. Mosasaurs were a group of large, aquatic squamates (relatives of modern-day lizards and snakes) which became the dominant marine predators towards the end of the Cretaceous period.
The Mesozoic Era [3] is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods.It is characterized by the dominance of gymnosperms such as cycads, ginkgoaceae and araucarian conifers, and of archosaurian reptiles such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea.
The Mesozoic marine revolution (MMR) refers to the increase in shell-crushing (durophagous) and boring predation in benthic organisms throughout the Mesozoic era (251 Mya to 66 Mya), along with bulldozing and sediment remodelling in marine habitats. [1] The term was first coined by Geerat J. Vermeij, [2] who based his work on that of Steven M ...
Marine mammal adaptation to an aquatic lifestyle varies considerably between species. Both cetaceans and sirenians are fully aquatic and therefore are obligate water dwellers. Pinnipeds are semiaquatic; they spend the majority of their time in the water but need to return to land for important activities such as mating, breeding and molting.
The recently extinct Steller's sea cow was the largest known sirenian to have lived, reaching lengths of 10 metres (33 feet) and weights of 5 to 10 tonnes (5.5 to 11.0 short tons). [2] Sirenians have a large, fusiform body which reduces drag through the water and heavy bones that act as ballast to counteract the buoyancy of their blubber. They ...
The additional weight may have stabilized the animal at the water's surface. Alternatively, it could have given Mesosaurus greater momentum when gliding underwater. [17] While many features suggest a wholly aquatic lifestyle, [17] Mesosaurus may have been able to move onto land for short periods of time. Its elbows and ankles were restricted in ...
Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply [1] [2] and 90% of habitable space on Earth. [3] Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. [4]
However, no evidence for a species-area effect has been found in more recent and better characterized portions of the geologic record. [ 51 ] [ 52 ] Another possibility is that reduced seafloor spreading associated with the formation of Pangaea, and the resulting cooling and subsidence of oceanic crust , may have reduced the number of islands ...