I took matrix (about 4.5 gallons total) this May from 4 different areas on the M&M Ranch in Nebraska. I washed and sieved the matrix at home and was left with around 1.5 gallons of matrix to search. The three group pictures below represent the nicest specimens that I found in the matrix from each of the three Oligocene Brule Formation areas (I found at least another five hundred or so broken and damaged specimens). If you look closely at the pictures you can see mammal teeth, jaw fragments, vertebrae and other bones. There are also lizard jaw fragments, osteoderms, and vertebrae as well as some snake vertebrae and possibly a couple of amphibian vertebrae. There are also a good number of claws which look to be from mammals. Pictures of individual specimens from the Oligocene portion of the ranch are also below. I will post the group picture and individual pictures of the Eocene Chadron Formation specimens from the fourth area of the ranch at a later time.
If you mouse over the pictures you will see the file name which has the specimen size and my best effort at identification. I am currently reviewing a number of papers so I can eventually id more of these specimens.
Here are the group pictures of the nicer specimens from the three Oligocene areas of the ranch. I could have taken many more individual pictures but just ran out of time and energy.
Here are some mammal jaw fragments. A lot of these jaw fragments are rodent but there are also insectivore jaw fragments with some from bats:
Here are some Mammal teeth:
Additional mammal teeth:
Here are a number of claws which are probably all from mammals:
Here is a claw that was somewhat different from all the others:
Most of these lizard specimens are probably from Peltosaurus granulosus.
Here are some lizard jaw fragments:
Here are a number of lizard osteoderms. Notice the two different distinctive shapes. I am thinking the shape difference is from different areas on the body of Peltosaurus granulosus versus from a different species of lizard.
Here are front and back pictures of two lizard osteoderms. The shape of the first specimen was very common and I found a good number of specimens like it. The second specimen was the only one with that shape that I found. But again I think the shape difference might be from body position.
I found a good number of Lizard vertebrae. Here are a couple:
I found a good number of snake vertebrae. Snake vertebrae are diagnostic and are used to describe and id different species of snakes. However, I do not have the expertise to id these any further:
Here is a Salamander vertebra. This is the specimen that I am the most excited about.
Here are a few vertebrae that I am not 100% sure about which are probably reptile: