Remarks: Body loricate, dorsoventrally
flattened, shape elliptical, oval or vase shaped, foot long retractile, annulated and terminating in to tuft of cilia.
Posterior to the median fins, the peduncle continues to taper dorsoventrally
until the first expansion of the caudal fin is reached (Figs 2D, 8C).
They are paired, elongated and dorsoventrally
flattened organs (Fig.
Abdomen: Very broad, slightly compressed dorsoventrally
Pinniped cervical vertebrae have large triangular neural canals; their zygapophyses are smaller and less pronounced than for the Manasquan vertebra; and their centra are elongated laterally rather than dorsoventrally
Tibiae, metatarsi and tarsi of leg I-II and tibiae and tarsi of palp dorsoventrally
Antennular peduncles stout, somewhat depressed dorsoventrally
, contiguous, thus mesial faces flat; first segment unarmed on distolateral and distomesial margins; dorsal surface with low elevation proximolaterally, but without conspicuous proximolateral tubercle; stylocerite broad, closely appressed to peduncle, reaching distolateral angle of second segment, lateral margin notably convex; second segment nearly as long as broad to slightly longer than broad, with moderately large distomesial tooth.
1) Shape of caudal basibranchial: The basilbranchial (= urohyal) was flattened dorsoventrally
(depressed) in some species, but slender, not depressed, in others.
These were the following: 1) carapace width (CW), measured laterally, across the widest point of the carapace; 2) carapace depth (CD), measured dorsoventrally
, extending from the highest point of the dorsal carapace surface to the lowest point on the ventral surface of the thoracic plate; and 3) carapace base (CB), measured ventrally, between the distal edges of the second segment of the last walking legs, with the legs folded flush against the carapace.
compressed, indistinctly segmented with two pairs of posteriorly-projecting spines ventrally.
The combination of characters that identify the fossil to Leptotyphlops include absence of a neural spine; zygosphene wide and thin; prezygapophyseal facets elongated and strongly anteriorly directed; posterior ends of neural arch extended medially; condyle and cotyle dorsoventrally
compressed; hemal keel indistinguishable from centrum; and no subcentral ridges.
Anterior and posterior nares close to eye and to each other, internarial distance 7 to 13 times in snout length; anterior naris in short tube, posterior border of tube not reaching posterior naris when reflected; posterior naris oval, much larger than anterior naris, with long axis of oval running dorsoventrally