Original Description: Edward Hallowell in 'Proceedings of the Academy of Natural Sciences of Philadelphia' 1852 (203-205); "On a new genus and two new species of African serpents".
Holotype: ZMB 8335 (not located) [Thrasops pustulatus] (Reptile Database)
Key to Central and West African species of the genus Thrasops:
1. More than 188 ventrals –> 2
Fewer than 188 ventrals –> 3
2. 13 or 15 dorsal scale rows –>T. flavigularis
17 to 21 dorsal scale rows –>T. jacksonii
3. Dorsal scales keeled –>T. occidentalis
Dorsal scales smooth –> 4
4. 13 dorsal scale rows; cloacal scale single –>T. batesii
15 to 19 dorsal scale rows; cloacal scale divided –>T. aethiopissa (Chippaux, 2012)
Thrasops flavigularis Species Characteristics:
"Ventrals: 191-214
Dorsal Scale Rows: 13-15 rows at midbody
*Dorsals much longer than the ventrals; no enlarged occipitals
Abdominal Scuta: 207
Sub-Caudal: 146" (Hallowell, 1852)
Lowland forest (Hallowell, 1852)
Color: Dark brown upon the upper part of the head, and upon the temples ; lighter upon the sides ; chin and throat yellowish white ; neck yellowish white, spotted with black ; body and tail jet black ; lighter upon the abdomen. (Hallowell, 1852)
Original Description: "The head presents the form of a triangle truncated anteriorly, depressed above posteriorly; rostral plate pentangular, broader below than above, rounded in front; there are two nasal plates with the nostrils between them; the anterior nasal is very large; there is a loral plate, also large and more or less quadrangular in shape ; there is but one ant-ocular, which is broad above, its upper surface extending inward between the posterior frontal and the supra-ocular; there are three post-oculars, the two upper of nearly equal size, the inferior long and slender; there are two anterior and two posterior frontals, the posterior rather larger than the anterior; the vertical is pentagonal, much broader anteriorly; the supra-oculars are large, broad behind, narrow in front; the occipitals are broad and short, their transverse diameter being equal to their length; there are two temporal plates behind the posterior ocular, the posterior much larger than the anterior; there are eight superior labials, the fourth and fifth forming part of the orbit, the sixth and seventh are the largest; the eyes are very large; there are four rows of teeth in the upper jaw; nine plates margin the lower jaw on each side; the neck is contracted; the body long and slender, thicker in the middle, covered above with long and narrow carinated scales; those nearest the abdomen are shorter and broader than the rest; tail covered with smooth imbricated scales, broader than long." (Hallowell, 1852)
Body Diagnostics: Length of head 1 inch 4 lines ; greatest breadth 6 J lines ; length of body 3 ft .5 inches 2i lines ; length of tail 1 ft. 6 inches 8 lines ; greatest circumference 2f inches. (Hallowell, 1852)
Size:
"Largest female: 210 cm
Largest male: 170 cm
Maximum Length: 240 cm." (Hallowell, 1852)
