preaxialmost part of tarsal skeleton proximal tarsal bone fibulare In salamanders this element is aproximatelly rounded, whereas in anurans it is an elongate, cylindrical bone with the proximal and distal heads fused to the heads of the tibiale One of two element that constitute the basal row of tarsals. The fibulare constitutes the preaxial element. In salamanders this element is aproximatelly rounded, whereas in anurans it is an elongate, cylindrical bone with the proximal and distal heads fused to the heads of the tibiale.[AAO] One of two elements that constitute the basal row of tarsals. The fibulare constitutes the preaxial element[AAO]. astragalus AAO:0000913 UBERON:0012126