MORPHOMETRIC ANALYSIS OF THE AMERICAN CROCODILE (CROCODYLUS ACUTUS)

When comparing fossil tracks, particularly in the same assemblage, identifying the number of track makers is of great interest to ichnologists. To accomplish this task, various features of the tracks are surveyed and the tracks that are most similar are assigned to an ichnospecies and, by extension, potentially the same trackmaker. This method works well with trackways and prints that have distinctly different morphological features. However, when considering prints that share a similar morphology, there is a possibility that the tracksite contains tracks that are a collection of prints from one species in various stages of growth rather than several adult species that share similar autopodial morphology. The extent of variation in autopodial morphology can affect the extent of variation found in trackways and understanding the extent of variation within a species can help resolve this issue. In this regard, several (ca. 60) wild specimens of the American crocodile (Crocodylus acutus) were captured and measured for morphometric analysis. Preliminary results show a close correlation (little variation) between the size of the animal (length of the animal, manus and pes lengths) and several autopodial measurements. These preliminary results suggest certain limits or allowances on intraspecific variation that may be present in a fossil crocodylian track assemblage; and, by extension, possibly other extinct archosaurs.