Kilianicaris Van Straelen, 1923

Laville, Thomas, Forel, Marie-Béatrice & Charbonnier, Sylvain, 2023, Re-appraisal of thylacocephalans (Euarthropoda, Thylacocephala) from the Jurassic La Voulte-sur-Rhône Lagerstätte, European Journal of Taxonomy 898 (1), pp. 1-61 : 15

Genus Kilianicaris Van Straelen, 1923

Type species

Kilianicaris lerichei Van Straelen, 1923 by monotypy.

Original diagnosis (literal translation from Van Straelen 1923a)

The overall shape is more angular, sub-quadratic in the posterior region and with a large rostrum expressed anteriorly. Tergal carina rises, especially in the rostral region. Lateral carinas are quite low. The rostrum is proportionally wider than long. The spiny posterior process is poorly delineated. Likewise for the postero-lateral processes that are slightly expressed.

Emended diagnosis

Thylacocephala with a rounded shield in lateral view, a rounded rostrum, a convex posterior part of the ventral margin, a falciform, tuberculate, dorso-lateral carina, eleven styliform, posterior trunk appendages, including elongate terminal trunk appendages.

Remarks

Schram (2014) suggested that Kilianicaris might be related to Ostenocaris Arduini, Pinna & Teruzzi, 1984 , forming the Ostenocarididae Schram, 2014 . He proposed that both taxa “have fused the posteriormost 8 trunk somites of the series of 16 into a posteriorly directed lobe”. This lobe corresponds to the putative telson that we describe in most of La Voulte-sur-Rhône taxa (see below) and is therefore not only present in Kilianicaris and Ostenocaris . In addition to this misconception, many morphological differences exist between both taxa. As pointed out by Schram (2014), Ostenocaris lacks a rostrum while Kilianicaris has a rounded rostrum. Moreover, they present differences in the overall shape of the shield (trapezoidal for Ostenocaris vs rounded for Kilianicaris ), in the morphology of their anterior margin (proverse vs straight), in the ornamentation of their dorsal margin (serrate and carinate in Kilianicaris ), in the morphology of their dorso-lateral carina and in the number of posterior trunk appendages (9 vs 11).