Tarsal plates are triangular when the ratio in the second expression is less than or equal to 1.6, and trapezoidal when the ratio is greater than 1.6. The authors did not include their measurements of the dimensions of the tarsus, and only reported the percentage of tarsal plates that were sickle, triangular, or trapezoidal. Using the theoretical tarsus above, the ratio of the second expression would instead be.