Since it’s clear that Europasaurus evolved from larger sauropod ancestors, the most likely explanation of its small size was an evolutionary adaptation to the limited resources of its ecosystem–perhaps a remote island cut off from the European mainland.

Known specimens vary in total length from 1.7 metres (6 feet) in juveniles to 6.2 metres (20 feet) in the largest adult. When alive, the largest specimen probably weighed about 500 kg (about 1,100 pounds), roughly the same weight as a present-day cow.

Germany. The dinosaur had little food to eat and little space to roam. It never grew! named their new discovery Europasaurus (yoor-oh-pah-SAWR- us).

Evolutionary cascade of the sauropods Undoubtedly, their long necks allowed them to reach food other animals couldn’t, which made a bigger size more advantageous for them. Their long necks relied on two key traits: hollow, or pneumatized, bones of the spine, as well a small head, which allowed the neck to be light.

Dinosaurs lived during the Triassic, Jurassic and Cretaceous. During these periods, the climate was much warmer, with CO₂ levels over four times higher than today. This produced abundant plant life, and herbivorous dinosaurs may have evolved large bodies partly because there was enough food to support them.

Blue whale

The closest living relatives of Tyrannosaurus rex are birds such as chickens and ostriches, according to research published today in Science (and promptly reported in the New York Times).

chimpanzee

Paleontologists think feathers may have first evolved to keep dinosaurs warm. But while a young T. rex probably had a thin coat of downy feathers, an adult T. rex would not have needed feathers to stay warm.

We and dinosaurs share body plans based upon four limbs. Although our skeletons have been modified in different ways, we have many of the same types of bones (the bones of our limbs and hands are a good example), and this all goes back to our swamp-dwelling common ancestor almost 400 million years ago.

The Human Edge: Finding Our Inner Fish One very important human ancestor was an ancient fish. Though it lived 375 million years ago, this fish called Tiktaalik had shoulders, elbows, legs, wrists, a neck and many other basic parts that eventually became part of us.

There is nothing new about humans and all other vertebrates having evolved from fish. According to this understanding, our fish ancestors came out from water to land by converting their fins to limbs and breathing under water to air-breathing.

Humans do have a tail, but it’s for only a brief period during our embryonic development. It’s most pronounced at around day 31 to 35 of gestation and then it regresses into the four or five fused vertebrae becoming our coccyx. In rare cases, the regression is incomplete and usually surgically removed at birth.