r/SacredEarthCommunity

Most people think of mosasaurs as fully marine predators — and for good reason. They’re typically found in ocean deposits and are often associated with open marine ecosystems.

But there’s an ongoing discussion in paleontology about whether some mosasaurs may have entered — or even adapted to — freshwater environments in certain regions. Fossil discoveries from inland deposits have raised interesting questions about habitat flexibility, behavior, and how rigidly we define “marine” reptiles.

The idea isn’t that mosasaurs were river animals in the way modern crocodilians are — but the evidence does suggest their ecological range may have been broader than traditionally assumed.

If anyone wants a deeper breakdown of the fossil evidence and interpretations, I put together a detailed article here:
https://sacredearthminerals.com/freshwater-mosasaurs/

Curious to hear thoughts from others who’ve looked into this topic.

A Pakistan specimen featuring lazulite and pyrite. The first thing that stands out is how well the lazulite shows against the matrix, which gives the whole piece a really sharp look.

The pyrite is a nice secondary feature, but the blue lazulite is definitely the star here. Posting a video so the surface detail and overall character come through properly.

Polished malachite from the Congo showing classic banded structure.

Once it’s polished, the internal patterns really stand out — tight curves, layered growth, and strong contrast between the darker and lighter greens.

Malachite always has a way of looking almost fluid once the surface is finished.

An Enchodus tooth I found in the field from a Cretaceous creek in New Jersey.

Enchodus is often called the sabertooth herring because of those long, distinctive teeth. This was a fun one to find in the creek, especially since pieces like this can be easy to miss if you’re not paying close attention.

A cool little reminder of the kinds of marine fossils that can still turn up in New Jersey creeks.