what is the land like where mesosaurus fossils are found?

Mesosaurus fossils are found in rock layers that used to be shallow lakes, lagoons, and coastal waters, not in high mountains or deep-ocean rocks.

Ancient land setting

• The land where Mesosaurus fossils are found today was once covered by shallow water : coastal seas, lagoons, and freshwater or slightly salty lakes.

• Over time, mud and silt on these lake and lagoon bottoms hardened into sedimentary rock, preserving the animals where they sank into the soft sediment.

What the ground is like now

• Today these fossils occur in sedimentary rocks (like shale and limestone) that formed from those ancient muddy and sandy bottoms.

• On the surface, this land is often dry and rocky, forming plains or low hills in places like eastern South America and southern Africa, where erosion has exposed the fossil layers.

What this tells scientists

• Because the rocks show they formed in shallow water, scientists infer that Mesosaurus lived in lakes, lagoons, and calm coastal environments rather than in the deep open ocean.

• The fact that the same kinds of rocks and fossils occur in both South America and southern Africa supports the idea that these regions were once joined as part of the supercontinent Pangaea.

In classroom terms: the land where Mesosaurus fossils are found used to be watery (lakes or shallow seas), but now it is mostly dry land made of old, layered sedimentary rock.