Cretaceous microfossil sorting Field Museum of Natural History in Chicago October 16-23, 2024

[Joseph Fossil]

I've been continuing my awesome Internship work with Late Cretaceous microfossils at the Chicago Field Museum of Natural History (aka the Best Museum in Chicago). The micro fossils are 68-66 Million Years old and are from the Maastrichtian Cretaceous age Hell Creek Formation in what is now the U.S. States of North Dakota, South Dakota, and Montana.

 

Here are some more interesting micro-fossils I've found recently these past two weeks.

 

At least two fragments of large Dromaeosaurid teeth (the first one with a crown length of at least 0.5 mm.).

 

 

 

 

 

Specimen 1

 

 

 

 

Specimen 2

 

I checked the IDs with my colleagues and we decided to give the two specimens a special taxon categorization.  

 

 

 

 

 

[C2fossils]

Cool!

[Joseph Fossil]

Some Unknown Specimens

 

 

Unknown 1 (Possibly a Lizard Jaw)

 

 

 

Unknown 2

 

 

 

 

Unknown 3

 

 

 

Unknown Mammal tooth 1

 

 

 

Unknown Mammal tooth 2 

 

 

 

Unknown Theropod (maybe Richardoestesia?)

 

 

 

Jaw fragment of a Scapherpeton tectum (amphibian) Individual 

 

 

 

Page Identification

[jpc]

cool stuff.  

 

As for ID's, based on this photo, I am going to call the first one a lizard jaw.  It would be nice to see the teeth a bit better. 

No2.. fish scale.  Show this to Lance Grande if you get a chance.  He should be able to tell you what fish it is from. 

No3... does this have a split root like a ray tooth?  That is the vibe I am getting from it.

No4... multituberculate molar, need size and better pix to ID it beyond that. 

second mammal tooth, lower molar of a non-multitubeculate.  The lower 'shelf' of this tooth is called the talonid.  It will have three little cusps on its edge.  If two of those are very close to each other, then it is a marsupial, if not then it is a 'regular mammal'... a placental.

small theropod teeth, yes, I owuld call these Richardoestesia. 

and lastly, Scapherpeton looks good for the last one. 

 

 

 

 

[Joseph Fossil]

A Tyrannosaurus rex tooth specimen

 

 

 

 

 

 

 

Thracosaurus jaw specimen?

 

 

 

 

Unknown Theropod 2

 

 

 

 

Myledaphus Specimen 1

 

 

 

 

Myledaphus Specimen 2

 

[Joseph Fossil]

56 minutes ago, jpc said:

cool stuff.  

 

As for ID's, based on this photo, I am going to call the first one a lizard jaw.  It would be nice to see the teeth a bit better. 

No2.. fish scale.  Show this to Lance Grande if you get a chance.  He should be able to tell you what fish it is from. 

No3... does this have a split root like a ray tooth?  That is the vibe I am getting from it.

No4... multituberculate molar, need size and better pix to ID it beyond that. 

second mammal tooth, lower molar of a non-multitubeculate.  The lower 'shelf' of this tooth is called the talonid.  It will have three little cusps on its edge.  If two of those are very close to each other, then it is a marsupial, if not then it is a 'regular mammal'... a placental.

small theropod teeth, yes, I owuld call these Richardoestesia. 

and lastly, Scapherpeton looks good for the last one. 

 

 

 

 

 

@jpc Thanks for the IDs. I appreciate it!!!