Schmidt, 1947
Dunn's mud turtle
Recognition
The elongated, oval, uniformly dark-brown carapace (to 17.5 cm) is slightly depressed, and unkeeled in adults, or slightly tricarinate in juveniles. Carapacial scutes are slightly overlapping, and the carapace is constricted at the bridge. Vertebrals 1 and 5 are broader than long, but 2-4 are longer than broad; the 1st touches the 2nd marginals. The marginals form a raised rim to the shell and are sharply set off from the pleural scutes. Marginal 10, and occasionally also the 11th, is elevated above the level of those preceding it. The narrow plastron is double hinged and notched posteriorly. Plastral forelobe width is less than 40% and the hindlobe width is less than 35% of the maximum carapace length. The plastral formula is: abd > an > hum > gul > fem > pect. Bridge length is 21-26% of the maximum carapace length. Axillary and inguinal contact occurs. Plastron and bridge are yellow with dark seams. The head is broad, with a projecting snout, and the upper jaw is moderately hooked. An extensive rostral scale covers most of the dorsal skull, but is not posteriorly bifurcated. There are four chin barbels. The head is dark brown dorsally but lighter laterally (with some mottling) and ventrally. Neck, limbs, and tail are gray brown. Vinculae are present on the thighs and crura of the male, and the tail of both sexes ends in a horny spine.
In addition to the clasping organs on their hindlegs, males grow larger and have long, thick tails. The shorter female (to 15 cm) has a small tail.
Distribution
Kinosternon dunni is known only from waterways in the Department del Chocó, Colombia.
Habitat
This species lives in small streams, where it burrows beneath the leaf litter covering the bottom.
Natural History
Kinosternon dunni apparently reproduces throughout the year, laying several clutches of about two eggs each (Medem, 1961). Eggs are ellipsoidal (45 x 25 mm) with brittle shells. Medem (1961) found mollusk remains in the digestive tract.
Remark
K. dunni is most closely related to the rare K. angustipons.
IUCN Red List Status (1996)
Vulnerable (B1+2c).