part of part of develops from develops from insect metatarsus insect prothoracic leg insect prothoracic tarsal segment insect prothoracic metatarsus T1 Ts1 FBbt:00004670 T1 tarsal segment 1 First tarsal segment of the prothoracic leg. Proximally, it articulates with the tibia and distally with the second tarsal segment. Its surface is covered with eight longitudinal rows of bristles and with transverse rows of bristles (TR) in the anterior compartment, between proximo-distal rows 7 and 8. There is sexual dimorphism in the number of TRs (transverse row bristles, TR). In males, 2 TRs are replaced by the sex comb and one central bristle. prothoracic tarsal segment 1 prothoracic basitarsus UBERON:6004670 insect presumptive prothoracic metatarsus