Genus Uroctonites Williams & Savary 1991
Prosoma. Anterior carapacial margin more or less bilobed, with deep rounded anterior median indentation.
Mesosoma. Pectinal tooth counts 8-12 in males, 7-10 in females. All female pectinal teeth similar in size and shape, and with sensorial areas.
Metasoma. Dorsal carinae of segments I-IV with an angular termination; terminal denticles not distinctly enlarged. Ventral submedian carinae paired; on at least segments II-IV distinct, granular. Segment V with ventromedian carina linear (not bifurcated distally).
Chelicerae. Ventral margin of the cheliceral movable finger smooth to crenulate; fixed finger lacking ventral denticles. Serrula well developed distoventrally on movable finger.
Pedipalps. Patella: Inner face with basal tubercles moderately developed; lacking inner longitudinal carina. Chelal carinae: Ventromedian carina absent, producing flattened ventral chelal face. Dorsomarginal, digital, and ventroexternal carinae well developed, typically granular. Chela dentition: Terminal denticles not prominent, conically shaped. Chela fixed finger with primary denticle row divided into five to six subrows of denticles, these are flanked by six inner accessory denticles. Chela movable finger with primary denticle row divided into six subrows of denticles, these flanked by six to seven inner accessory denticles. Denticles of primary denticle row subconical, rounded.
Trichobothrial Pattern. Patella with two ventral trichobothria along ventroexternal carina (the third ventral trichobothrium is positioned on the external face). Four V trichobothria on chela manus. Chelal trichobothria ib positioned on the distal end of the chela palm, rather than on the fixed finger. Chela finger trichobothrium est about equidistant between et and esb.
Legs. Basitarsi and telotarsi without setal combs. Telotarsi ventrally with a median row of small spinules that are flanked distally by a pair of slightly larger spinules. Ventromedian spinule row flanked laterally by spiniform setae.
Hemispermatophore. Mating plug absent. Lamellar hook blunt to rounded, positioned at base of ectal edge of distal lamina.
Included species. - Uroctonites giulianii Williams & Savary 1991, Uroctonites huachuca (Gertsch & Soleglad 1972), Uroctonites montereus (Gertsch and Soleglad 1972), and Uroctonites sequoia (Gertsch and Soleglad 1972).
Similar taxa. See Uroctonus Thorell, Pseudouroctonus Stahnke, and Vaejovis C. L. Koch (mexicanus group).
Remarks. - This genus was established, information concerning its four species updated, and a key to their identification provided by Williams & Savary (1991). Members of this genus are found on exposed rock surfaces and talus slopes and under rocks in xeric, montane, cave, and coastal environments. Their occurrence as geographically isolated species with restricted ranges suggests they are relicts of a previously more broadly distributed lineage. Of the four known species, all appear to reside in small, isolated populations, except for the more broadly distributedUroctonites montereus.
The members of Uroctonites are distributed as two species pairs, which are separated from one another by the intervening crest of the Sierra Nevada. To the west of the Sierra Nevada crest the sister species Uroctonites montereus andUroctonites sequoia occur. Both have a single subdistal tooth (rarely two) on the dorsal tine of the movable cheliceral finger (a synapomorphy) and seven supernumerary denticles on the movable finger of the pedipalp (a symplesiomorphy). The ventral series of trichobothria on the pedipalp chela is compressed in these two species, with the distance between trichobothria Vt and Vst usually equaling less than two-thirds the distance between Vb and Vsb. The San Joaquin Valley, which lies between the known ranges of these two species, and a possible association of Uroctonites sequoia with caves and limestone outcrops, suggest that both geographical and ecological isolation have played a role in their speciation.
The sister speciesUroctonites giulianii andUroctonites huachuca are distributed to the east of the Sierra Nevada crest. Both have two subdistal teeth (rarely one) on the dorsal tine of the movable cheliceral finger (a symplesiomorphy) and have six supernumerary denticles on the movable finger of the pedipalp (a synapomorphy). The ventral series of trichobothria on the pedipalp chela is not as compressed in these species as it is in the western species pair, and the distance between chelal trichobothria Vt and Vst usually equals more than two-thirds the distance between Vb and Vsb. These two species appear to be montane relicts, with Uroctonites giulianiinow restricted to the Inyo Mountains, White Mountains and eastern Sierra Nevada of California, and Uroctonites huachuca restricted to the Huachuca Mountains and Santa Rita Mountains of Arizona.