Article: Statistical analysis and presentation of trinucleid (Trilobita) fringe data

The current notation and methods of data presentation for the pits of the trinucleid fringe are reviewed and some shortcomings noted. Using a sample of Trinucleus fimbriatus Murchison investigations show that (i) operator errors in selecting half-fringes were negligible, (ii) major features of the pit distribution are not dependent on the size of specimen, (iii) statistically there are no significant differences between the left and right half-fringes, although particular individuals commonly exhibit some asymmetry. It is considered most probable that these conditions hold true in all trinucleids and that numerical studies should be applied throughout taxonomic studies of the group.