Triassaraneus andersonorum Selden, 1999

Selden, Paul A., Anderson, Heidi M. & Anderson, John M., 2009, A review of the fossil record of spiders (Araneae) with special reference to Africa, and description of a new specimen from the Triassic Molteno Formation of South Africa, African Invertebrates 50 (1), pp. 105-105 : 111

Triassaraneus andersonorum Selden in Selden et al., 1999

Figs 3–5

Material examined: SOUTH AFRICA: KwaZulu-Natal: Holotype PRE/F 18560a (part) and 18560b (counterpart), immature or mature female from Upper Umkomaas ‘Waterfall Locality’ ( UMK III ). Eastern Cape: PRE/F 17234 Tel 111, immature from Telemachus Spruit locality ( Anderson & Anderson 1983, 1984). All material from from Member Z of the Late Triassic (Carnian) Molteno Formation and deposited in the palaeobotanical collection of the South African National Biodiversity Institute , Pretoria.

Description of new specimen: The specimen is preserved as brown, organic cuticle on a pale, grey-brown shale. The shale is splintery and pieces readily fall away. Scattered throughout the shale are abundant plant remains, including on the fossil slab a male cone of Ginkgoopsida. Parts of at least three legs are preserved, though it is not possible to determine which legs these are. No body parts are preserved. On the right in Figs 4, 5 is a nearly complete walking leg, showing most of the femur to the tarsus. On the left are some of the opposing walking legs, but less complete. Note that in Fig. 5A , there is a loose piece of matrix bearing parts of a leg; this became detached and is not present in Fig. 5B (under ethanol), which therefore reveals more of the tibia of on the left-hand walking legs. The walking legs bear setae on all podomeres, and larger, thin spines on all podomeres except the tarsus. These spines, for example on the right leg patella and tibia, are long, thin and erect.Although tarsal claws cannot be seen,it is certain from the shape of this podomere (only preserved on the right side) that its distal end is present, so the claws must be small. There is no evidence of tarsal scopulae or claw tufts. The legs appear to be rather short, although the only one which is nearly completely preserved, on the right, may be a third leg,which is commonly short in orbicularians (orb-web weavers).

Figures

Fig. 3. Holotype of Triassaraneus andersonorum from the Triassic (Carnian) Molteno Formation, Upper Umkomaas ‘Waterfall Locality’ (UMK III), KwaZulu-Natal, South Africa: (A) photograph in incident light under ethanol, (B) camera lucida drawing. Scale bar = 1 mm.

Figs 4, 5. T. andersonorum specimen PRE-F 17234 Tel 111 from Telemachus Spruit: (4) camera lucida illustration, (5) actual fossil dry (A) and under ethanol (B). Abbreviations: fe – femur, mt – metatarsus, pa – patella, ta – tarsus, ti – tibia. Scale bar = 0.5 mm.