Redescription of Macrobiotus tridigitus Schuster, 1983 and the erection of a new genus of Tardigrada (Eutardigrada, Macrobiotidae) Author Kaczmarek, Łukasz Author Michalczyk, Łukasz text Journal of Natural History 2006 2006-09-18 40 19 - 20 1223 1229 http://dx.doi.org/10.1080/00222930600844443 journal article 10.1080/00222930600844443 1464-5262 4658038 Schusterius tridigitus ( Schuster, 1983 ) comb. nov. ( Figures 1–7 ) Description Holotype ( paratype ): body length 235.0 (295.0) ( Figure 1 ). Body colourless, eyes absent. Cuticle smooth, without granulation or pores. Mouth terminal, probably with 10 peribuccal lamellae ( Figure 2 ). Bucco-pharyngeal apparatus of Macrobiotus type with ventral lamina 16.0 [ 59.3 ] (19.0 [ 57.6 ]) long and with one bend in anterior part ( Figures 2, 3 , 5, 6 ). Buccal tube 27.0 (33.0) long and 3.5 [ 13.0 ] (4.0 [ 12.1 ]) wide. Stylet supports inserted on buccal tube walls at 21.0 [ 77.8 ] (26.0 [ 78.8 ]) of its length. Oral cavity armature poorly developed. On dorsal side all teeth absent. On ventral side first two bands of teeth absent and only one median tooth (in shape of transversal ridge) present in third band. Pharyngeal bulb oval with three oval macroplacoids without constrictions, similar in length, and microplacoid. First macroplacoid 4.0 [ 14.8 ] (4.5 [ 13.6 ]) long, second 3.0 [ 11.1 ] (4.0 [ 12.1 ]), third 3.0 [ 11.1 ] (4.0 [ 12.1 ]). Microplacoid 2.0 [ 7.4 ] (2.3 [ 7.0 ]) long. Macroplacoid row 12.0 [ 44.4 ] (15.0 [ 45.5 ]) long, placoid row 14.0 [ 51.9 ] (18.0 [ 54.5 ]) long. Figures 1–4. Schusterius tridigitus comb. nov. (1) Habitus (holotype). (2, 3) Buccal apparatus: (2) lateral view, holotype; (3) ventral view, paratype. (4) Claws of the third pair of legs. Claws similar to Calcarobiotus type claws (primary branches very similar in length) with 2-1-1-2 configuration, Y-shaped but with extremely developed, very long and thin accessory points connected to primary branch by flexible light-refracting portion ( Figures 3, 4 , 7 ). Measurements of external claws in paratype : accessory points of I pair 11.0 [ 33.3 ]; primary branch of II pair of legs 8.0 [ 24.2 ]; secondary branch of II pair of legs 7.5 [ 22.7 ]; accessory points of II pair 11 [ 33.3 ]; primary branch of III pair of legs 9.0 [ 27.3 ]; secondary branch of III pair of legs 8.0 [ 24.2 ]; accessory points of III pair 12.5 [ 37.9 ]; primary branch of IV pair of legs 7.0 [ 21.2 ]; secondary branch of IV pair of legs 7.0 [ 21.2 ]; accessory points of IV pair 10 [ 30.3 ]. Smooth lunules present on all legs. Cuticular bars and other cuticular structures on legs absent. Figures 5, 6. Schusterius tridigitus comb. nov. , buccal apparatus. (5) Mid-section. (6) Ventral view (paratype). Eggs unknown. Type locality South America, Argentina , Tierra del Fuego , Sierra Martial. Material examined Holotype and paratype : Argentina , Tierra del Fuego , Sierra Martial , altitude 2000–2500 feet (tree line), cryptogams, 19 January 1979 , coll. Arthur M. Shapiro. Holotype and paratype are deposited in the Entomology Collection in Bohart Museum , University of California , Davis , USA .