The Curious Case of Elrhaz Formation Theropod Teeth

The Elrhaz Formation from Niger is about 125-112 million years old and is rich in Early Cretaceous dinosaur material. Some iconic dinosaurs are from this formation, Suchomimus, Ouranosaurus and Eocacharia, along with the famous giant crocodylomorpha: Sarcosuchus. Material, especially teeth and claws have become available to the market. The problem, how to tell what is what?

The issue: The Jurassic and Cretaceous dinosaur deposits are very near to each other and local fossils diggers often mix the material together. Their color and preservation are quite similar, which makes it hard. The key to this is studying the matrix, color and preservation of two different dinosaur teeth: From the Elrhaz Formation (Cretaceous): Suchomimus, and from the Tiouraren Formation (Jurassic) the spoon shaped sauropod teeth. I was lucky to get a large set of teeth that appear to be all from the Elrhaz Formation. This has allowed me to be able to begin to identify the non Suchomimus theropod teeth.

There appears to be 3 large theropod teeth, not including Suchomimus. Eocarcharia, a rare true Carcharodontosaurinae and a Metricanthosaurid/allosaurid.

Eocacharia is a carcharodontosauridae probably closer to Acrocanthosaurus than Carcharodontosaurus. Their teeth are recurved, compressed (thin) and the mesial serration reaches about ¾ of the way down the tooth. The serration count ranges from 13 - 15 per 5mm on both distal and mesial serrations. The mesial carinae are slightly offset from the distal carinae. These teeth are the second most common non Suchomimus theropod teeth.

The Carcharodontosaurinae are quite rare, as I have seen a couple. These teeth closely resemble Carcharodontosaurus teeth in shape. The tooth I was able to measure has a mesial serration count of 12 per 5 mm.

The Metricanthosaurid/Allosaurid are probably a bit controversial and many are probably labelled as the Jurassic Afrovenator. These teeth have a mesial/distal serration count of around 10-11 serrations per 5mm. The distal serrations only go about ½ way down the tooth. These teeth are not symmetrical, as the mesial carinae is off set like many allosaurus teeth. However the distal serrations ending ½ way indicate it might be metriacanthosaurid. These teeth are not as compressed as Eococharia and Carcharodontosaurinae teeth. These teeth appear to be the most common and can be the largest. 

There are also abelisaur teeth from Kryptops, but some of these teeth might be from the noasaurid Afromimus. There are two types of serration count, one where mesial and distal serration are 15-17 per 5 mm, and one where the mesial is 12-13 per 5 mm and the distal is 16-17 per 5 mm. Some of these teeth can get over 1”, which indicates the species is  Kryptops, the larger teeth all have the 15-17 per 5 mm serration count on the distal/mesial carinae. Is the 12-13 per 5 mm and the distal is 16-17 per 5 mm Afromimus, maybe, but more research is needed to determine that. 

At the Daily Rex we strive to do our best at labelling species. Not everyone will agree, which is OK.

In the pictures the teeth are as follows from left to right: Eocacharia, Metricanthosaurid/Allosaurid, Carcharodontosaurinae

Read more →

Facts and Fictions of Commercial Paleontology

Fact: Commercial Paleontologist sells their fossils.

Fiction: All fossils are rare and belong in museum. Most museums do not have room for all the fossils they find, and many academic institutions will not collect fossils that are of new or rare species. There are dozens of bone beds for sauropod dinosaurs in Utah but no one wants to dig them because of the cost, size and low scientific importance to the academic institution. 

Fact: Fossils can end up in private collections when sold.

Fiction: Once a fossil ends up in private hands it has lost all scientific value. This is false, many academics choose to ignore privately collected fossil. Most collectors will gladly lend their fossils to institutions for research. However, sadly, many academics choose to ignore amazing finds they do have access to. 

Fact: Most commercial paleontologist do it for the love of science. Most commercial paleontologist are not rich, the headline grabbing T Rex skeleton prices are the exception not the norm. 

Fiction: No dinosaur skeleton shouldn't cost hundreds of thousands of dollar. It takes years, expensive equipment, land, and thousands of hours of labor to dig, mount and display a dinosaur skeleton. Some skeletons can take hundreds of thousands of dollar to dig, mount and display. 

Fact: There are fake fossils out there. Fake fossils exist, always buy from a trusted source. Some fossils are part real and part reconstructed, thee is nothing wrong with this the deal just needs to tell you.

Fiction: That fossil was glues and thus is it reconstructed. Almost all dinosaur fossils need to be glued, especially teeth. Gluing them back together does not mean the fossil is reconstructed.

Fact: Commercial paleontologists who dig in the US must dig on private land. Any vertebrate fossil found on federally owned land is illegal to collect. And even legally collected found on federal land cannot be sold. 

Fiction: Fossils collected long ago on government land cannot be sold. This is false, fossil collected pre laws can be sold. However, it is hard to prove this one way or another.

Fact: Fossils are the gateway to science. The science are so vitally important for kids to learns and owning a real fossils can spark that curiosity of science at a young age!

Fiction: Commercial paleontologist don't like academic paleontologist. This is 100% false, we love working with them. We just don't like being called names by them. 

Read more →