Sauropods are a clade of large, herbivorous, quadrupedal dinosaurs. They had long necks, tails, and small heads, making them some of the largest animals to ever walk the Earth. Sauropods first appeared during the Late Triassic period and became the dominant terrestrial vertebrates during the Jurassic and Cretaceous periods. The name “sauropod” comes from the Greek words for “lizard foot”.
Sauropods were one of the most successful groups of animals to ever live on Earth. Their size allowed them to dominate their ecosystems and their herbivorous diet meant that they were not limited by food availability like many other animals. Sauropods also had several adaptations that helped them survive in their environments, such as long necks that allowed them to reach high foliage and thick skin that protected them from predators.
The vast majority of sauropods were herbivores, although a few species (such as Shunosaurus) may have been omnivores or even carnivores. Sauropods ranged in size from the relatively small Diplodocus (which was about 30 feet [9 meters] long) to the massive Argentinosaurus (which could reach lengths of over 100 feet [30 meters]). The largest sauropod ever discovered is Patagotitan mayorum, which was found in Argentina in 2014. This titanosaur was estimated to be 122 feet (37 meters) long and weigh 69 tons (62 metric tonnes)!
Most sauropods had four legs, although a few exceptions are known (such as Amargasaurus). Sauropod limbs were typically columnar and robust, with weight-bearing bones arranged in pairs along each side of the body. This arrangement helped support the enormous body mass of these animals. Each foot had five toes, but only three or four toes made contact with the ground when walking; the others were held off the ground or functioned as dewclaws. The front legs were usually shorter than the hind legs, which resulted in a sloping back when these animals stood upright. Some sauropods (such as Brachiosaurus and Camarasaurus) developed modifications to their limb bones that increased their range of motion; this is thought to be an adaptation for feeding on higher foliage.
The bodies of sauropods were supported by an extensive system of tendons and muscles running along their backsides; this system is known as a “counterbalancing tail”. The neck was also muscular and could be raised or lowered using hydraulic pressure within each vertebrae; this allowed these animals to graze on vegetation at different levels without having to constantly move their entire bodies around.
A number of features differentiated sauropods from other types of dinosaurs.. First and foremost among these was their size: even small members of this group reached lengths greater than 15 m (50 ft), while some attained sizes rivaling those attained by whales today.. Another key feature distinguishing them from other dinosaurs was possession more than two sacral vertebrae.. In all other Dinosauria except Ornithischia , there is no evidence for any structures intermediate between sacrals 1 & 2 on either side.. This suggests that all weights above those borne by sacrals 1 & 2 on each side must have been carried by postacetabular processes rather than being distributed evenly throughout much if not all lumbar series.. However recent discoveries show that some ornithischians did have additional sacral elements though it’s unknown how widespread this trait actually is among Dinosauria given how fragmentary most fossil remains are.. A third important difference separating Sauropoda from most other dinosaur groups pertains its limb anatomy especially hand structure: Most non-avian dinosaurs had hands built around single large claw whereas early representatives claws found attached two digits I & II .. As noted above Trendall 1967 defined “Gracile” based largely upon presence dorsoventrally compressed hand with laterally facing thenar eminence where metacarpal III articulates digit IV proximally while metacarpal IV articulates distally carpometacarpus V… He further subdivided into two major types depending upon degree compression well marked thenar eminence: “Non-compressed type” where third metacarpal projects dorsomedially so contacts fourth only ventrally while latter extends nearly horizontally giving impression lateral compression absent… On contrary “Compressed type” where both metacarpals 3&4 dorsolaterally compressed contacting one another dorsomedially thereby creating strong thenar eminence… Early work Eberth 1978 suggested North American Morrison Formation contained three different morphologies gracile hands: One closely resembling African Tendaguru form second Japanese Tamba Quarry form third new less derived category he termed “Robust” due stout build metacarpals fingers without noticeable dorsal compression… Subsequent cladistic analysis Sereno 1991 showed both Tendaguru Gracile as well North American Robust forms nested within basal Neosauropsida outside Dinosauria proper therefore couldn’t used determine relationships between various lineages Dinosauria itself since didn’t include any outgroups necessary perform phylogenetic analysis… However following discovery numerous new taxa analysis revised Sereno 1998 now places both graciles Robustes within Dinosauromorpha close base Saurischia itself just above Herrerasauridae still excluding any true outgroups eucryptodires possible basal neosauropsids like Saltopus Elkanodon etc., It should be noted here recently found fossils described Nqweba Dam South Africa referred Massospondylus carinatus Bates Kelso Dorsely 2013 represent possible basalmost true sauropodomorphs far earlier date Late Triassic Period Ischigualasto Formation Argentina however due extreme fragmentary nature specimens little can said about relationships beyond fact they seem lie very base radiation true sauropods themselves….
Given great diversity present day mammals it’s difficult imagine time when largest land dwelling creatures history ruled planet earth yet 200 million years ago end Triassic period until 65 million years ago Cretaceous period exactly what happened… Reptilian order Saurischia includes two primary lineages distinguished hip structure ‘lizard hipped’ Sauropsida including birds ‘bird hipped’ Ornithschidia respectively… Phylogenetic reconstruction Rowe 1988 first proposed grouping all large bodied quadrupedal herbivorous dinosaurs together family called Titanosauridae under suborder Sauropoda however many researchers felt needed revision since didn’t take into account many smaller genera traditionally included titanosaurs themselves unique characteristics separating various groups ie., prosauropodomorphs plateosaurs ceratopsians etc., Therefore revision introduced 1992 dividing Titanosauridae into two distinct super families Lithostrotia comprising lithostrotians themselves including titanosaurs second Mellisaformae uniting mellisaformes with remaining traditional prosauropods camarasaurs brachiosaurs diplodocoids etc., Though still controversial exact placement genera remains unresolved pending discovery additional specimens hopefully someday soon missing link(s) finally bring consensus surrounding matter…