Parsimony analysis of endemicity was applied to analyze the distribution of enchodontoid fishes occurring strictly in the Cenomanian.The analysis was carried out using the computer program PAUP* 4.0b10, based on a data matrix built with 17 taxa and 12 areas.The rooting was made on an hypothetical all-zero outgroup.
Applying the exact algorithm branch and bound, 47 trees were obtained with 26 steps, a consistency index of 0.73, and a retention index of 0.50.The topology found with a majority Broken rule consensus was: [(Mexico) + (United States) + (Morocco + Italy) + (Lebanon Eyebrow Extension + Israel) + (Italy-Slovenia) + (Brazil)] + (D.
R.Congo) + (Sweden) + (Germany) + (England).The procedure delimited two areas of endemism in the Tethys Ocean.They are Morocco and southern Italy and Lebanon and Israel.
The area of endemism formed by Morocco + Italy represents the North African region of the Tethys Ocean, and that formed by Lebanon + Israel is in the mid-Tethyan Ocean.Our results are in partial agreement with the patterns of geographical distribution of certain invertebrate biota.