Steve Cunningham, Baltimore, Maryland, USA
From Mike Folmer's collection, Fisher/Sullivan site, early Eocene (Ypresian stage) Potapaco Member of the Nanjemoy Formation. A Random sample of 9,250 S. macrota teeth were sorted to position and then separated into two subsets labeled "a" and "b" as shown below.
Photos by S. Cunningham. Teeth have been coated with sublimated
ammonium chloride to enhance detail.
All positional characters are derived from, and comparable to, extracted C. taurus teeth.
Distinguishing characters that define each subset are consistent from anterior to posterior teeth and throughout ontogeny. The 8 files for each lateral subset shown below are arbitrary. It is not know how many files S. Macrota had. However, the teeth depicted below represent the array of positional changes in the study set.
In the study set of 9,250 teeth, subset "a" totaled 5,665 teeth; while subset "b" totaled 3,298. The total count of first upper anterior teeth is 287 suggesting that only one subset has this position. The UA1 is consistent in characters and cannot be differentiated into subsets.
|Click here to see the positional tooth count and graph of positions for each subset|
Click on a tooth, group or row of teeth to see the larger image.