The first of the tarsal segments of the adult leg. It is located between the tibia and the second tarsal segment and is longer than the other tarsal segments. It has 8 longitudinal rows of bristles around the circumference. [ FlyBase:FBrf0012178 FlyBase:FBrf0007734 FlyBase:FBrf0111704 FlyBase:FBim0000836 ]
Synonyms: 1st tarsal segment first segment of the tarsus tarsal segment 1 first tarsal segment basitarsus