Floridobolinae Keeton, 1959

Shelley, Rowland M. & Floyd, Samuel D., 2014, Expanded concept of the milliped family Spirobolidae Diplopoda: Spirobolida: Spirobolidea): Proposals of Aztecolini n. tribe and Floridobolinae / ini and Tylobolini n. stats.; (re) descriptions of Floridobolus and F. penneri, both Causey, 1957, and F. orini n. sp.; hypotheses on origins and affinities, Insecta Mundi 2014 (357), pp. 1-50 : 12-14

Subfamily Floridobolinae Keeton, 1959 , new status

Floridobolidae Keeton, 1959:1–2 ; 1960a:31 (key); 1960b:137. Hoffman, 1980a:77; 1982:695; 1999:48.

Deyrup, 1994:254. Shelley et al., 2000:20. Shelley, 2001a:243 .

Type-genus. Floridobolus Causey, 1957 .

Diagnosis. Body profile rounded/cylindrical or transversely ovoid ( Fig. 33 ). Gnathochilarial mentum with or without apical, knob-like convexity. Paraprocts slightly re-entrant or not, without marginal rims, not overhung by epiproct. Anterior gonopod telopodites fused or articulating with coxae, apically uncinate or not. Membrane caudal to appendages with or without sclerotized remnant of posterior gonopod sternum. Posterior gonopod coxal apodeme long/moderately long, oriented lengthwise in body. Telopodites with rounded apical lobes on short, thickened, expansions of caudal and/or anterior surfaces, with or without additional projections.

Description. Robust, rounded cylindrical/transversely ovoid, and glabrous/glossy Spirobolidae , narrowing and tapering caudad or on both ends. Apex of gnathochilarial mentum with or without elevated, knob-like convexity between lingual lamellae. Collum terminating above caudolateral corners of 2 nd pleurotergite. 7 th pleurotergites of males lengthened and expanded or not. Epiproct apically rounded, shorter than and not overhanging paraprocts; latter slightly re-entrant, with or without low marginal rims. Males with pregonopodal lobes on 2 nd –5 th or 3 rd and 4 th coxae. Anterior gonopod sternum narrow, expanding medially, with or without lobe, only slightly protruding between, and at most only barely separating, coxal endites ( Fig. 6 , 10 ). Membrane caudal to sternum with or without narrow, transverse, unattached sternal remnant. Coxal endites with or without distinct, prolonged medial lobes; telopodites fused with or articulating with coxae, with faint suture lines in former condition, distal extremities narrow, uncinate or not, demarcated from midlengths to varying degrees. Posterior gonopod coxa curved caudad, apodeme moderately long to long, oriented generally lengthwise inside body; telopodite upright and sublinear or curved varyingly mediad/dorsomediad; prefemoral process varying from small, nubbin-like vestige to larger but inconspicuous structure; acropodite with either anterior or both anterior and caudal margins extending variably mediad, demarcating central depression or cavity in latter condition, distal surfaces of extended margins thickened and variably lobed, distal lobe prolonged and curved downward/dorsad in one genus.

Components. Two tribes: Floridobolini Keeton, 1959 , and Tylobolini , Keeton, 1960.

Distribution ( Fig. 12 ). Floridobolinae occupy six areas, two each in Florida, the western US and adjacent Mexico, and one each in central Mexico and Guatemala. Floridobolini occupy Florida, and areas in western North America, inhabited by Tylobolini , include the continuous familial region along the Pacific Coast with the eastward expansion into Utah/Arizona, the triangular region in southeastern Arizona, and the Guatemalan point locality. The subfamilial area in central Mexico differs from that of the family in being farther southward, extending from southern Durango, Coahuila, and Nuevo León to Guerrero ( Chamberlin and Hoffman 1958; Keeton 1960a, 1966; Loomis 1968a; Hoffman 1980a, 1999; Shelley and Bauer 1997; Shelley 2002 a , 2010; Shelley and Stevens 2003; Bueno-Villegas et al. 2004; Shelley and Golovatch 2011; plus additional localities in the Appendix).

Origin. As it contains the most plesiomorphic component, Floridobolinae originated simultaneously with the family, which we arbitrarily date at <303 mya.

Tribe Floridobolini Keeton, 1959 , new status Figures 1–5 , 14–21 , 33

Type- and only component genus. Floridobolus Causey, 1957 .

Diagnosis. With the characters of the subfamily.

Description. Robust, transversely ovoid ( Fig. 33 ), and glabrous/glossy Spirobolidae with 47–50 pleurotergal rings, broadest around rings 12–13, narrowing and tapering at both ends, more so caudad. Apex of gnathochilarial mentum elevated into knob-like convexity between lingual lamellae. Mandibular stipes concave, rounded, and greatly expanded, with strong, elevated marginal rims forming shelves for antennae in resting positions. Collum terminating above caudolateral corners of 2 nd pleurotergite, anterior margin slightly excavated below levels of ocelli, ridge pronounced ( Fig. 1–2 ). 7 th pleurotergites of males not lengthened or expanded, subsimilar to adjoining rings ( Fig. 3–4 ). Epiproct broadly rounded apically, shorter than and not overhanging paraprocts; latter slightly re-entrant, without marginal rims ( Fig. 5 ). Legs not extending beyond lateral pleuroteral margins, invisible in dorsal view ( Fig. 3 ). Males with pregonopodal lobes on 3 rd and 4 th coxae only, former elongate dorsoventrally and with two closely appressed distal lobes extending to midlengths of 2 nd podomeres and directed caudad, triangular in ventral aspect and situated in situ between 4 th lobes, latter short, subtriangular in ventral aspect. Anterior gonopod sternum expanding mediad but without lobe and not protruding between coxal endites, at most only barely separating latter ( Fig. 14, 18 ); membrane caudal to sternum with narrow, unattached, transverse sternal remnant; coxal endites broad, margins lightly scalloped or curvilinear, medial corners not or only slightly extended; telopodites fused with coxae and with faint suture lines, distal extremities narrow, not uncinate, demarcated from midlengths to varying degrees ( Fig. 14, 18 ). Posterior gonopod coxal apodeme long, oriented lengthwise and extending caudad internally up to level of 10 th ring; telopodite subupright and post-like; prefemoral process small and inconspicuous, either a pyramidal, nubbin-like structure or minute enlargement of telopodital stem; anterior and caudal acropodital surfaces thickened and expanding mediad thereby demarcating narrow cavity or depressed area between them, apically lobed and rounded ( Fig. 16, 20 ); strong bifurcate projection, with rounded ventral and stronger, more variable dorsal branches ( Fig. 15, 17, 19, 21 ), arising distad from anterior surface; caudal surface with or without short, inconspicuous, closely appressed basal process with rounded apical and subapical lobes, latter directed submediad.

Distribution ( Fig. 13 ). Endemic to a latitudinal distance of approximately 248 km (155 mi) in central peninsular Florida, where it is known from Marion and Polk/Highlands cos.

Origin. The oldest and most plesiomorphic clade, Floridobolini constitutes the original lineage of both Spirobolidae and Floridobolinae and its arbitrary date of origin is the same, <303 mya.

Remarks. Noting the lack of a clear articulation, Keeton (1959) originally thought that the anterior gonopod coxa and telopodite were fused without a remnant of their boundaries, but with a cleared gonopod, he later ( Keeton 1960b) reported a faint suture line. Hoffman (1982) also observed that the podomeres are fused.

Figures

Figure 10. Relationships among spirobolid tribes, apomorphies are listed in table 1. F, Floridobolini. T, Tylobolini. A, Aztecolini. S, Spirobolini.

Figure 12. Distribution of Floridobolinae plotted against Cretaceous land patterns; submerged, marine Florida terrane and approximate maximal dimensions of the Western Interior Seaway in light blue. Ap, Appalachia. F, Floridobolus/Floridobolini. L, Laramidia. SA, Presumptive Source Area in the “northern Mexican Highlands.” Black lines and dot (delineated by the arrow), Hiltonius/Tylobolini. Red line, Tylobolus/Tylobolini. Green line and dot (in Florida), Floridobolus/Floridobolini. The area where Tylobolini/Hiltonius and Aztecolus overlap constitutes the presumptive source area.

Figure 13. Distributions of Floridobolini and Floridobolus. Star, type locality of F. orini. Black line, known and projected distributions of F. penneri on the Lake Wales Ridge. AR, course of the Apalachicola River in Florida. H, Highlands Co. M, Marion Co. P, Polk Co.

Figure 33. Ring profiles in Spirobolidae. Left two rings, transversely ovoid profile shown by Floridobolinae/ Floridobolini. Right two rings, rounded profile demonstrated by Floridobolinae/Tylobolini and Spirobolinae. Photo courtesy of O. McMonigle.

Figures 6–9. Comparison of Floridobolinae posterior gonopods. 6) Floridobolus penneri (Floridobolini), caudal view of caudal acropodital surface of holotype left posterior gonopod. 7) Hiltonius carpinus (Tylobolini), anterior view of right posterior gonopod of male from Cochise Co., Arizona. 8) H. pulchrus (Tylobolini), caudal view of right posterior gonopod of male from Riverside Co., California. 9) The same, caudal view of right posterior gonopod of male from Los Angeles Co., California. Fig. 7 is reproduced from Shelley (2010) with permission from the Center for Systematic Entomology; Fig. 8–9 are reproduced from Keeton (1960a) with permission from the American Entomological Society.

Figures 1–5. Floridobolus orini holotype. 1) Head, collum, and anterior pleurotergites, dorsal view. 2) The same, right sublateral view. 3) Entire body, dorsal view. 4) The same, dorsolateral view. 5) Paraprocts, epiproct, and caudal pleurotergites, caudolateral view.

Figures 14–21. Floridobolus spp., gonopodal features. 14–17) F. penneri holotype.14) Left anterior gonopod, anterior view. 15) Telopodite of left posterior gonopod, anterior view. 16) The same, caudal view. 17) Bifurcate projection of anterior surface of the same, anteriomedial view. 18–21) F. orini holotype. 18) left anterior gonopod, anterior view. 19) Telopodite of left posterior gonopod, anterior view. 20) The same, caudal view. 21) Bifurcate projection of anterior surface of the same, anteriomedial view. A and C, anterior and caudal surfaces, respectively, of posterior gonopod acropodite. at, anterior gonopod telopodite. ce, coxal endite. db, dorsal branch of bifurcate projection. s, sternum. vb, ventral branch of bifurcate projection. asterisk (*), prefemoral process. x, extraneous basal process.