Date of this Version
Mammalian Species, No. 761, pp. 1–5, 3 Figs. Dec. 2004.
CONTEXT AND CONTENT.
Order Soricomorpha, family Soricidae, subfamily Soricinae, tribe Blarinini, genus Cryptotis (Hutterer 1993; Repenning 1967). The species is part of the Cryptotis thomasi group (Choate 1970; Woodman 2002). Cryptotis meridensis is monotypic (Woodman 2002).
Cryptotis meridensis (Fig. 1) is one of the largest members of the genus; length of head and body is typically >83 mm. C. meridensis and the Mexican endemic, C. phillipsii, are the only species of small-eared shrews in which U4 (dental terminology follows that of Choate  and Choate and Fleharty ) frequently is absent. In C. meridensis, U4 is absent on 1 or both sides of cranium in 25% of individuals (n = 51), but more typically, U4 is reduced in size (averaging 19 ± 7% of surface area of U3, n = 48; mean 6 SD), often consisting of a simple, rounded peg (Woodman 2002). C. meridensis is not sympatric with any other soricid. However, identifying this species with certainty requires suites of characters. C. meridensis can be distinguished from its geographically closest congeners along the Cordillera Oriental of Colombia (C. brachyonyx, C. tamensis, and C. thomasi) by the absent or reduced U4. In addition, C. meridensis is larger than C. brachyonyx (length of head and body < 76 mm), has a relatively shorter tail, and has much paler dorsal and ventral coloration. Cranially, C. meridensis typically has a small to medium-sized foramen on posterior edge of tympanic process of 1 or both petromastoids (87%, n = 55), in contrast to the huge foramina present in C. brachyonyx, and U1–3 in C. meridensis are slender with concave posteroventral margins rather than massive with straight or convex margins (Woodman 2003). Compared with C. tamensis, C. meridensis is distinguished by a higher coronoid process; longer posterior mandible behind m3; typically 3 unicuspids (rather than 4) visible in lateral view of cranium; paler and less extensive dental pigmentation that extends into just the hypoconal basins of P4, M1, and M2 (rather than both hypoconal and protoconal basins); and a typically less complex M3. In contrast to C. thomasi, C. meridensis has darker pelage, a longer tail (averaging 34 ± 3 mm versus 24 ± 2 mm; mean 6 SD), small to medium-sized (rather than huge) petromastoid foramina, less emarginate upper dentition, and simple M3 (Woodman 2002).