(Rafinesque, 1814)
European Free-tailed bat
External characters (Table 57)
This is a large species of Tadarida with an average forearm length of 61.2 mm (58.4-63.9 mm) in extralimital specimens; 64 mm in the single specimen known from India. The wings are long, narrow and naked with a characteristically short fifth metacarpal, on average about 60-65% the length of the fourth metacarpal (Tte2). The wing membranes are inserted on the short tibia just above the ankle of each robust foot. The outer borders of the inner and outer toes are densely covered with short stiff hairs (Fig. 121) and a circular smooth pad is present on the sole of the foot. The thumbs are strong, each with a small circular pad situated ventrally at the distal end of each metacarpal. The naked interfemoral membrane is about half the length of the robust, muscular tail; it is supported by strong calcars (Fig. 118). The pelage is short, dense, soft and velvety; rather longer on the throat. According to Hill, 1963b, the only known specimen from India is 'brownish' on the back and grey on the ventral surface. The face is characteristically dog-like with relatively large eyes (Fig. 117). The muzzle is blunt; it projects noticeably beyond the upper lip which is very large and marked by many deep furrows. The upper margin of the nostril pad is broadly concave in the middle; the nostrils are subcircular and open ventro-laterally. The ears are also large with very broadly rounded tips; they are directed downwards so that their inner surfaces face ventrally and overhang the face (Fig. 117). Unlike Tadarida plicata (Tpl2), they are situated close to one another but are not joined at their anterior bases. The tragus of each ear is rather square in outline, but with the free corners bluntly rounded off, its anterior and upper margins are fringed with long hairs. The antitragus is large, its length about double its height.
Cranial characters
The skull (Tte1, Tte3) is relatively large and elongated with an average condylo-canine length of 22.2 mm (21.6-23.1 mm) based on extralimital specimens. The dorsal profile is essentially straight from the nares to the lambda but with a slight convexity over the anterior two thirds of the braincase and with an elevated portion posteriorly; these two convexities are separated by a concavity (Tte4). The braincase, like that of Tadarida aegyptiaca is smooth, low and broad. The sagittal crest is absent and the lambda is smooth and rounded; lambdoid crests are present laterally. The palate is very elongated and narrow. The basisphenoid has a central ridge and shallow ovoid pits laterally. The coronoid process of each half mandible is elevated to a height comparable to the tip of the lower canine; its posterior edge is long and shallowly regressed to the condyle; the angular process is well developed.
Dentition
- Upper toothrow length (C-M3) averages 8.7 mm (8.2-9.3 mm) in extralimital specimens (8.8 mm in the single specimen known from India). The teeth appear powerful in relation to the size of the skull. The single upper incisor (I2) is large, about half the height of the canine, inwardly sloping and widely separated from its fellow. The upper canine is moderately large, with a well defined, narrow cingulum but without accessory cusps. The first upper premolar (PM2) is small, circular in outline, situated in the toothrow, usually in contact with the canine; its crown area about one third to a half that of the upper incisor. The principal cusp (paracone) and the protocone of the second premolar (PM4) are well defined. M1 is slightly larger than M2; the metacone is predominant in both and each has a very distinct conical hypocone separated from the commissure of the protocone by a notch. M3 is comprised of a parastyle, mesostyle and metastyle and three commissures.
- The three pairs of lower incisors (occasionally two pairs, see Hill in Chaturvedi, 1964) are bifid, overlapping and closely crowded together; their cutting edges are situated below the well defined antero-internal cingular cusp of the lower canine. The first lower premolar (pm2) is three quarters or more the crown area and two thirds the height of the second (pm4). m1 and m2 are subequal, with all the cusps well formed. m3 is likewise complete, about two thirds the crown area of m2; the talonid is equal in crown area to the trigonid.
Variation
Hill, 1963b was not able to determine the race of the one specimen known from India. Its dorsal pelage was dark compared to that of the European nominate form T. t. teniotis or T. t. insignis from China. Ventrally, however, it lacked the brownish tinge evident in these subspecies and was more similar to that of T. t. rueppelli (Tte5) from Egypt and Arabia.