Unknown Mammal Molars

[jag2ut]

These molars were found along the Calvert Cliffs in MD. I do not think that these are too rare, but I was wondering if anyone had any insight on what kind of mammals these teeth came from. Especially the first one, which is my personal favorite. Thanks!

#1:

#2:

#3:

#4:

[calhounensis]

Occlusal (chewing surface) photos would help. But I'll take a shot, #1 looks like a horse, #2 is bison or bos, #3 looks like a carnassial, #4 is a bison or bos premolar.

#1, 2, and 4 are fairly common. If #3 is a carnassial it could be quite rare. Carnivores are much rarer in the fossil record. In addition to the occlusal, a labial and lingual shot would be helpful.

Edited July 22, 2014 by calhounensis

[Harry Pristis]

Welcome to The Fossil Forum, jag2ut.

Identification of mammal cheek teeth typically require straight-on images of the lingual, labial, and occlusal surfaces. Here are some other tips:

Do you have editing software that came with your camera or with your scanner? Use the image-editing software (or download shareware from the Internet).

You can be as creative as you want to be with the editing software, but the following basic things will improve anyone's images:

GROUP IMAGES of more than a few fossils are not effective. The more individual fossils in an image, the greater the amount of table-top is in the image. Viewers cannot see the details of a fossil that might take up less than five percent of the total image. Photograph a single fossil (or two or three, if they're tiny), and post that image.

LIGHT IT UP. Use as much ambient light as possible to reduce shadows...two light sources are a minimum. Eliminate yellowed images caused by tungsten filament bulbs by switching to the new compact flourescent bulbs. CFLs come in a "daylight" (6500K) version that you can use in any (non-dimming) fixture and produce very little heat.

BRIGHTEN AND CONTRAST. BRIGHTEN the image until the fossil appears slightly washed, then adjust the CONTRAST until the fossil is bright and sharp and is a good color-match. Practice this until you get a feel for it.

CROP, CROP, CROP. Again, use the image-editing software to crop the image to only what is pertinent. Leave only a narrow margin around the fossil. The more of your kitchen counter-top in the image, the smaller the fossil image will be.

REDUCE THE FILE SIZE. The images directly from a camera usually are too large for posting directly to a forum. You can constrain the proportions of your image to produce exactly the size that works best (I routinely use 700 Kb - 2.0 Mb for my images now). Save in JPEG format.

[MarcoSr]

A major problem with finding horse and bos/bison teeth in float in the MD/VA area is determining whether they are fossils versus being recent. Teeth can get color and some mineralization fairly quickly. If they are found in situ in a formation (unless near the surface where someone could have buried a horse or cow) or the tooth morphology doesn't match the extant species then you have a fossil. Fossil horse and bison teeth are not common from the MD/VA area, although common in other areas of the US. Recent horse and cow teeth are found fairly often.

Marco Sr.

[RichW9090]

I've seen some gravel/coarse sand filled channel cuts in the top of the Miocene formations along the Calvert Cliffs - one of which yielded a very nice diamond back terrapin shell which is in the Calvert Marine Museum.

[MarcoSr]

I've seen some gravel/coarse sand filled channel cuts in the top of the Miocene formations along the Calvert Cliffs - one of which yielded a very nice diamond back terrapin shell which is in the Calvert Marine Museum.

There is a Pleistocene sand/gravel layer which overlays the formations in different places in the MD/VA area. Normally the layer doesn't contain anything or the fossils are very scarce in it which I always thought was very odd. It is almost impossible to dig in but it does put fossils into float.

Marco Sr.