Henicops dentatus, Pocock, 1901

Hollington, L. M. & Edgecombe, G. D., 2004, Two New Species of the Henicopid Centipede Henicops (Chilopoda: Lithobiomorpha) from Queensland and Victoria, With Revision of Species from Western Australia and a Synoptic Classification of Henicopidae, Records of the Australian Museum 56, pp. 1-28 : 4-6

Henicops dentatus Group

Diagnosis. Henicops with 29–40 (most commonly 36) antennal articles, with a relatively gradual change in length of articles along antenna; Tömösváry organ deep, outer edge at margin of cephalic pleurite; TT7, 9, 11 and 13 with subquadrate emargination (posterior margin with transverse medial sector with independent curvature from lateral sectors); three moderate sized teeth on dental margin of maxillipede coxosternum; groove in accessory denticle field lacking on mandibular teeth; mandibular aciculae variable in structure, differentiated into some with pronounced serrations on both margins and others with a simple margin along most or all of length; ventral branching bristles of mandible lacking spine-like branches on basal part; three tarsomeres in legs 1–12; four tarsomeres in legs 13 and 14, basitarsus and distitarsus with two tarsomeres each; five tarsomeres in leg 15, basitarsus having two, distitarsus three.

Assigned species. Henicops dentatus Pocock, 1901a (= H. oligotarsus Attems, 1911 ); H. tropicanus n.sp.

Discussion. The diagnosis above lists characters that unite Henicops dentatus and H. tropicanus n.sp. that are either unique within Henicops or permit distinction from H. maculatus or other species. Several of these can be regarded as synapomorphies for H. dentatus and H. tropicanus . Character polarity is evaluated in the context of Henicops being sister to a clade that includes Lamyctes , Analamyctes , Easonobius and Lamyctopristus (Edgecombe et al., 2002; Edgecombe, 2003a, 2004a; Edgecombe & Giribet, 2003b) (see synoptic classification below).

Indistinct grooves in the accessory denticle field on the mandibles ( Figs. 5D,I, 10A,F) are restricted to the H. dentatus Group within Henicops . Grooves or grooved ridges (see Fig. 14D,F for their presence in H. milledgei ) are observed in most Henicopini , including other members of the Lamyctes-Henicops Group ( Fig. 2A). The “notched” margin of tergite 7 in the H. dentatus Group ( Figs. 3, 7A) is distinctive for those two species within Henicops , though the same shape of this tergite is observed in some other Henicopinae , e.g., within Paralamyctes and in Zygethobiini . Tergite shapes were noted by Pocock (1901a) as subquadrately emarginate TT7, 9, 11 and 13, serving as a distinguishing character of H. dentatus and H. tropicanus relative to H. maculatus and H. milledgei .

A differentiation of the mandibular aciculae into an outer row with serrated margins and an inner row with simple or weakly scalloped margins ( Figs. 5G, 10C,D) is shared with Henicops milledgei ( Fig. 14I). This differentiation is basally (the entire basal half of the bristle lacks spines in H. dentatus : Fig. 5H), but branch evenly along their distal part ( Figs. 10E, 14H). This is also apparently apomorphic relative to the evenly spine-covered bristles in H. maculatus (Edgecombe et al., 2002: fig. 5C), which have spines on their bases. The latter state is possessed by other taxa in the Lamyctes-Henicops Group (for Lamyctes , see Edgecombe et al., 2002: fig. 6D, Edgecombe & Giribet, 2003a: fig. 27; Fig. 2B herein for H. brevilabiatus ) and other Henicopini generally.

The relatively even length of the antennal articles in the H. dentatus Group is potentially apomorphic relative to the groups of shortened articles occurring in pairs in other congeners because other genera of the Lamyctes-Henicops Group (e.g., Lamyctes , Analamyctes , Easonobius , Lamyctopristus ) have the paired, shortened articles. The deep, submarginally positioned Tömösváry organ in the H. dentatus Group ( Figs. 6L, 9D–F) is unique within Henicops , but is shared by most non- Henicops Henicopini . The deep, submarginal organ is thus apparently plesiomorphic relative to the shallow organ situated medially on the cephalic pleurite in H. maculatus (Edgecombe et al., 2002: fig. 1G) and H. milledgei ( Fig. 15D,E). This character suggests that the H. dentatus Group is possibly sister to all other species of Henicops .