Male - habitus (Fig. 1). Length 9.0 mm, width 3.2 mm; shape in dorsal view elongate, length/width ratio = 2.8, widest near anterior 1/6 of elytra; shape in lateral view slightly compressed. Integument uniformly dark (black); surface sculpture of pronotum and elytra homogeneously foveate to lacunose, with deep, densely and regularly arranged, subcircular impressions, otherwise rugulose; integument covered with setae and scales, each most apparent on rostrum and legs; setae regularly arranged, dark brown, short and recurvate; scales circular and apparently densely arrangement and light to dark brown, though not well preserved in the type specimen.

Mouthparts. Mandibles equilateral, with 5-8 fine setae; mandibular scar positioned apicolaterally, projected. Maxillae with maxillary palps apparently 3-segmented (2 projecting palpomeres visible). Labium with prementum cordate, slightly wider than long; labial palps apparently 3-segmented.

Rostrum. Length 1.85 mm, rostral/pronotal length ratio 0.6, rostral length/width ratio 2.0 (though rostrum laterally compressed due to fossilization). Rostrum in dorsal view rectangular, anteriorly widened, anterodorsal margin weakly emarginate; epistoma with nasal plate (see Vaurie 1963) slightly angled in relation to posterior rostrum region, depressed, V-shaped; dorsal surface with a deep, median sulcus. Rostrum in lateral view anteriorly slightly expanded, occipital sutures extending to subapex and visible; scrobe lateral, nearly extending along entire rostrum though terminating anteriad of eye; antennal insertion near anterior 1/3. Antennae 11-segmented; scape extending to posterior margin of eye, and passing over eye (in idealized position); funicle 7-segmented, funicular antennomeres elongate, clavate; club 3-segmented, small, similar in length to funicular antennomeres V-VII.

Head. Eyes small, globular (strongly roundly protruded), laterally positioned, separated by distance shorter than anterior-to-posterior length of each eye; outline in lateral profile elliptical (horizontally more extended), anterior and posterior margins more strongly rounded, and with an anteocular invagination (see Franz 2012) extending from anteroventral to dorsoventral edge of eye. Head not constricted posteriad of eyes.

Thorax. Pronotum in dorsal view elongate-tubular, length/width ratio 1.5, pronotal/elytral length ratio 0.43; widest near mid point; surface foveate to lacunose (including lateral regions), lacunae somewhat variable in size and arranged in an off-set, honeycomb-like pattern; median sulcus absent. Pronotum in lateral view tubular, slightly arcuate; anterolateral margins straight (without postocular lobe), postocular vibrissae absent. Scutellum exposed by elytra, small, subcircular. Epipleura challenging to observe (distorted, obscured), though apparently similar to those of Scelianoma elydimorpha sec. Franz and Girón (2009). Prothoracic ventrite with anterior transverse sulcus; procoxal cavities positioned near mid point, contiguous. Mesothoracic ventrite with plumose-scopiform scales; mesocoxal cavities narrowly separated. Metathoracic ventrite challenging to observe; metacoxal cavities widely separated. Metendosternite not observed.

Legs. Prothoracic and metathoracic legs each longer than mesothoracic legs, generally similar to those of males of Scelianoma elydimorpha sec. Franz and Girón (2009). Profemoral/pronotal length ratio 0.8; profemur ventrally inermous. Protibial/profemoral length ratio 1.1; protibia slightly arcuate, apically exanded; anteromesal margin with 5-8 roundly triangular teeth, size increasing apically, each tooth distally with 1 brownish, spiniform seta; protibial apex with anterior margin truncate, setal comb absent, promucro similar in length to protarsal claw; protarsus with tarsomere I longer than II; II and III similar in length and jointly as long as V; protarsal claws paired, separate, simple. Mesotibiae and metatibiae nearly straight, apically obliquely truncate; metatibial apex with a narrow (linear) outer bevel ("corbel enclosed"; see Thompson 1992).

Elytra (Fig. 1). Length/width ratio 2.2; widest near anterior 1.4; anterior margins jointly minimally wider than posterior margin of pronotum, nearly straight; humeri absent; lateral margins slightly angulate: diverging along anterior 1/6, subrectate and slightly converging along posterior 1/6; posterior margins narrowly rounded. Elytra in lateral view with dorsal outline subplane along anterior 5/6, posterior 1/6 with distinctly angled, straight declivity, mesal elytral margin projected along angulation. Elytra with striae I-IX complete, stria X incomplete (challenging to observe); striae wider than intervals; punctures large, deep, foveate to lacunose, subcircular to elliptical, and arranged from stria to stria in an off-set, honeycomb-like pattern; intervals slightly elevanted and rounded.

Wings. Absent.

Abdomen. Venter with only abdominal ventrites VI and VII visible (and displaced by process of fossilization), each similar in length, and VII with posterior margin widely rounded. Pygidium entirely covered by elytra.

Terminalia. Terminalia not unambiguously observed; however, located just to the left side of the amber-included specimen are several displaced, distorted chitinous structures that apparently include the male spiculum gastrale and median lobe in more or less parallel orientation to the remainder of the specimen. Accordingly (with aforementioned caveats), the presumed spiculum gastrale is similar to that of Scelianoma elydimorpha sec. Franz and Girón (2009), and slightly shorter than the median lobe which narrowly linear in dorsal view and narrow and straight in lateral view, though more arcuate (inflected) along posterior 2/5, with dorso- and ventrolateral margins posteriorly continuously converging, and terminating in a narrowly rounded apex.

Female. Unknown.

Generic placement. Scelianoma compacta [FZ2017] shares with Scelianoma elydimorpha Franz and Girón sec. Franz and Girón (2009) numerous phylogenetically informative traits inferred in Franz (2012) that substantiate this generic placement (see also Franz and Girón 2009 and Tables 1, 2, 3, 4, 5, 6). They include: character 18(1): rostrum with one dorsal, median sulcus; character 23(0): scrobe (of antenna) passing over eye in lateral profile; 26(1) rostrum (ventral side) with occipital sutures anteriorly extending to subapex of rostrum, anteriorly ascending and visible in lateral profile; 34(1): head with an anteocular invagination, extending from anteroventral to anterodorsal edge of eye; 35(1): head with eyes in dorsal profile entirely positioned on lateral surface of head; 58(2): metatibial apex with an outer bevel ("corbel enclosed"; see Thompson 1992); 62(1): elytra with humeri absent; 66(1): elytra with declivity in lateral profile strongly angulate (Franz and Girón 2009); and 83(1): wings not developed (absent). This combination of character states is shared only between Scelianoma compacta [FZ2017] and Scelianoma elydimorpha sec. Franz and Girón (2009), rendering them monophyletic and thus congeneric in our expanded analysis.

Close extant relatives of Scelianoma Franz and Girón [FZ2017] include members of Artipus Sahlberg sec. O'Brien and Wibmer (1982) that frequently display a wider shape, a wider and dorsally more narrowly (and non-continuously) sulcate rostrum (character 40[1] of Franz 2012), with the scrobe and hence the antennal scape passing ventrad of the eye in lateral profile (and idealized position), and characteristically irregular (punctate to linear) dorsal pronotal foveae (character 43[1] of Franz 2012). We note, however, that Artipus sec. O'Brien and Wibmer (1982) is likely not a monophyletic, comprehensively sampled entity, and indeed a revision of this entity is underway (N.M. Franz, in preparation). The revision is unlikely to alter present inferences regarding the identity of Scelianoma [FZ2017].

Scelianoma [FZ2017] is also distinct from other extant Caribbean groups such as Apotomoderes Dejean sec. Franz (2010b) and Melathra Franz sec. Franz (2011) which have a head with a conspicuous postocular constriction (character 32[1]), a profemoral tooth (character 52[1]), and a less abruptly angulate elytral declivity (character 66[0]); all in accordance with Franz 2012).

Franz and Girón (2009) preferred a placement of Scelianoma sec. Franz and Girón (2009) in the tribe Eustylini Larcordaire 1863 [non-focal], but this was not supported in Franz (2012). We defer to future studies to assess the validity of this tribal placement.

Differential diagnosis. Scelianoma compacta [FZ2017], in addition to being extinct and recorded from Dominican amber, is differentiated from the extant, southwestern Puerto Rico-inhabiting Scelianoma elydimorpha sec. Franz and Girón (2009) by having a smaller size and less elongate body form, a more strongly foveate to lacunose dorsal sculpture on the pronotum and elytra, and a more slender rostrum, although the latter appears to have been laterally compressed by the process of fossilization. If our interpretation of the Terminalia of Scelianoma compacta [FZ2017] is valid, then then the posterior region of the median lobe is less arcuate in this species than in Scelianoma elydimorpha sec. Franz and Girón (2009).

The epithet - "thick, firm, compact" (Brown 1956) - refers both to the shorter, more compact habitus of Scelianoma compacta [FZ2017] in comparison to Scelianoma elydimorpha sec. Franz and Girón (2009), and to the 'compressing and distorting' effect that the fossilization process appears to have had on the specimen.

Scelianoma compacta [FZ2017] is known only from the examined Dominican amber inclusion ("SEMC 339"; see Material) of the Burdigalian time period. The specific mine of origin for this inclusion is unknown.

Unknown.

Female - habitus (Fig. 2). Length 8.6 mm, width 3.6 mm; shape in dorsal view oval to elongate, length/width ratio 2.4, widest near mid region of elytra; shape in lateral view elongate to pyriform. Integument uniformly dark brown to black; surface sculpture punctate, subcircular punctures largest on pronotum; integument entirely and homogenously covered with setae and scales, each apparently pale yellow in color, with no maculae apparent, darker and with metallic aspects on the legs; setae short and linear, densely and regularly arranged, directed posteriad, appressed, scales very small, subcircular, overlapping.

Mouthparts. Mandibles equilateral, with 3-5 coarse and several finer setae; mandibular scar positioned apicolaterally, projected. Maxillae not apparent, covered by labium (however, the maxillary palps are 3-segmented in extant members of Tropirhinus Schoenherr [FZ2017]). Labium with prementum cordate, equilateral; labial palps apparently 3-segmented.

Rostrum. Length 1.3 mm, rostral/pronotal length ratio 0.8, rostral length/width ratio 1.1. Rostrum in dorsal view equilateral to rectangular, dorsolateral margins nearly straight and distance between them anteriorly gradually widening, anterodorsal margin with a distinct, narrow, V-shaped mesal emargination; epistoma with nasal plate (see Vaurie 1963) weakly developed, angled in relation to posterior rostrum region, slightly depressed, V-shaped carina absent; dorsal surface with a median, wide, glabrate, weakly projected carina (or elevation), extending from posterior margin of epistoma to mid point between eyes. Rostrum in lateral view slightly arcuate, tumescent in dorsal mid region; scrobe lateral, slightly arcuate, posteriorly directed ventrad of eye, though also terminating anteriad of eye; antennal insertion near anterior 1/4. Antennae 11-segmented; scape slender, slightly arcuate, extending to posterior margin of eye, and passing ventrad of eye (in idealized position); funicle 7-segmented, funicular antennomeres elongate, weakly clavate, I and II similar in length, III to VII shorter, and increasingly so towards the apex; club 3-segmented, narrowly elongate, similar in length to funicular antennomeres V-VII.

Head. Eyes large, globular (strongly roundly protruded), dorsolaterally positioned, separated by distance similar to anterior-to-posterior length of each eye; outline in lateral profile elliptical (horizontally more extended), ventral margin less rounded.

Thorax. Pronotum in dorsal view equilateral to transverse, weakly convex, length/width ratio 0.85, pronotal/elytral length ratio 0.25; widest near posterior 1/3, lateral margins continuously rounded; surface punctate, with a wide, elliptical median sulcus (or impression) extending along anterior 1/2 of pronotum. Pronotum in lateral view equilateral; anterolateral margins with a small postocular lobe, and dorsad thereof with a tuft of 4-6 slightly longer, anteriorly directed setae ("postocular vibrissae", except these are not projecting from the postocular lobe but are dorsad of it). Scutellum exposed by elytra, small, escudate, posterior margins rounded. Epipleura with mespisternum triangular; mesepimeron dorsally oblique truncate; metepisternum linear, anteriorly widened; metepimeron entirely covered by elytron. Prothoracic ventrite with anterior margin widely emarginate; proxocal cavities positioned near mid point, contiguous. Mesothoracic ventrite with plumose-scopiform scales; mesocoxal cavities separeated by distance 1/3 as wide as each mesocoxal cavity. Metathoracic ventrite with median sulcus present as a large, transverse fovea positioned anteriad of posterior margin; metacoxal cavities separated by distance similar to width of each metacoxal cavity. Metendosternite not observed.

Legs. Prothoracic and metathoracic legs each slightly longer than mesothoracic legs (mesofemora shortest in comparison), generally similar to those of Diaprepes abbreviatus sec. Franz (2010a). Profemoral/pronotal length ratio 1.3; profemur ventrally inermous. Protibial/profemoral length ratio 1.2; protibia apically angulate-arcuate, width similar throughout; anteromesal margin with 5-8 small, triangular teeth, each tooth distally with 1 brownish, spiniform seta; protibial apex with anterior margin truncate, setal comb absent, promucro similar in length to protarsal claw; protarsus swith tarsomeres I and II similar in length, each slightly shorter than III which in turn is shorter than V; protarsal claws paired, separate, simple. Mesotibiae and metatibiae nearly straight, apically slightly expanded and obliquely rounded; metatibial apex with a narrowly elliptical outer bevel ("corbel enclosed"; see Thompson 1992).

Elytra. Length/width ratio 1.8; widest near mid region; anterior margins jointly wider than posterior margin of pronotum, slightly sinuate; humeri present, rounded; lateral margins continously rounded, nearly straight in mid region, more strongly converging in along posterior 1/4; posterior edges each with a short, narrowly triangular, ante-apical projection. Elytra in lateral view with dorsal outline subplane along anterior 1/2, thereafter continuously rounded (hence declivity convex), less so along posterior 1/8. Elytra with striae I-IX complete, stria X only apparent along anterior and posterior 1/3; striae similar in width to intervals; punctures separated by distance similar to width of each puncture; intervals slightly and roundly elevated; pale-colored scales and setae covering elytra homogenously, with no maculae apparent.

Wings. Present, yet not observed (covered by elytra).

Abdomen. Venter with segments III and IV jointed (see Thompson 1992 for segment homology), similar in length, and separated by sinuate suture; V-VII separate; V and VI jointly slightly shorter than IV, posterior margins elevated-projected; VII similar in length to IV, triangular, posteriorly narrowly truncate. Pygidium posteriorly narrowly rounded, covered by elytra.

Terminalia. Not unambiguously observable; however, the stylus and setae of the left coxite appear to project from the terminal opening, which is indicative of the female identity of the specimen (along witht the triangular ventral segment VII).

Male. Unknown.

Generic placement. Tropirhinus palpebratus [FZ2017] shares with (e.g.) Tropirhinus elegans (Guérin 1847) sec. Franz (2012) numerous phylogenetically informative traits inferred in Franz (2012) that substantiate this generic placement (see also Tables 1, 2, 3, 4, 5, 6). They include: 9(1): rostrum in lateral profile slightly arched and tumescent in mid region of dorsal surface; 16(1): rostrum dorsally mono- or tricarinate; 17(0): rostrum monocarinate, with one median, wide and rounded carina; 23(1): scrobe (of antenna) passing ventrad of eye in lateral profile; 31(0): head-rostrum transition in lateral profile continuous or only slightly angulate; 32(0): head in dorsal profile without a conspicuous postocular constriction; 34(0): head without an anteocular invagination; 58(2): metatibial apex with an outer bevel ("corbel enclosed"; see Thompson 1992); 67(1): posterior margins of elytra with an ante-apical, narrowly triangular projection; and 83(0): wings fully developed. The most parsimonious reconstructions furthermore postulates two wing properties that cannot be obversed in this amber inclusion, viz. 84(1): wings in proximal third with at least one patch of small, densely arranged denticles; and 85(2): patches of denticles in proximal region of wings distributed in rows along R (vein). This combination of character states is shared only between Tropirhinus palpebratus [FZ2017] and Tropirhinus elegans sec. Franz (2012) as coded in that latter analysis, and this correspondence of phylogenetically informative traits is the primary justification for assigning Tropirhinus palpebratus [FZ2017] to Tropirhinus [FZ2017].

We thereby assign to Tropirhinus [FZ2017] an expanded circumscription in comparison to (e.g.) Tropirhinus sec. O'Brien and Wibmer (1982), whose three members lack a postocular lobe and in turn have variously patterned metallic-colored maculae on the pronotum and elytra (see Guérin-Méneville 1847, Chevrolat 1877, Zhang et al. 2017). These and other apparent differences - e.g., only Tropirhinus novemdecimpunctatus (Fabricius 1781) sec. O'Brien and Wibmer (1982) has strongly protruding eyes - could be emphasized to justify the creation of a new genus-level name for the amber-preversed specimen under study. However, two kinds of considerations caution against this at present (see Vences et al. 2013). First, the characters and states that distinguish Tropirhinus palpebratus [FZ2017] from the other members of Tropirhinus [FZ2017] are frequently homoplasious in this greater lineage of Caribbean entimine weevils (as analyzed in Franz 2012 and Zhang et al. 2017). The presence or absence of a postocular lobe, or of postocular vibrissae, are variable traits within Diaprepes Schoenherr [FZ2017] (see also O'Brien and Kovarik 2001, Franz 2012). Metallic coloration patterns are often variable within and among the recognized members of (e.g.) Exophthalmus Schoenherr 1823 sec. Morrone (1999). Accordingly, our expanded genus-level concept Tropirhinus [FZ2017] entails primarily characters and states that appear to be phylogenetically 'labile' at low taxonomic levels. We consider this acceptable. Second, creating a new genus-level name for this specimen makes no tangible contribution to resolving the taxonomic identity of extant and closely related lineages, including members of Compsoricus Franz 2012 sec. Franz (2012), Pachnaeus Schoenherr 1826 sec. O'Brien and Wibmer (1982), Tetrabothynus Labram and Imhoff 1852 sec. O'Brien and Wibmer (1982), and the likely taxonomically misnamed Exophthalmus quindecimpunctatus (Olivier 1807) sec. Franz (2012) (therein incorrectly spelled) and Exophthalmus roseipes (Chevrolat 1876) sec. Franz (2012). The combination of an abundance of available genus-level names and still inadequate knowledge of the species-level diversity and phylogenetic relationships of the various aforementioned lineages (see also Zhang et al. 2017) makes it less appealing to create yet another genus-level name at this juncture.

Franz (2012) assigned Tropirhinus sec. Franz (2012) to the tribe Geonemini Gistel 1856 [non-focal], and this placement is not under taxonomic scrutiny here.

Differential diagnosis. Tropirhinus palpebratus [FZ2017], in addition to being extinct and recorded from Dominican amber, is readily distinguished from the extant members of Tropirhinus [FZ2017] by the presence of a small, postocular lobe (with a setal patch ventral thereof) and absence of metallic-colored pronotal and elytral maculae. Moreover, the eyes of Tropirhinus palpebratus [FZ2017] are more globular and protruded than those of Tropirhinus elegans sec. Franz (2012) and Tropirhinus tredecimpunctutatus (Guérin 1847) sec. O'Brien and Wibmer (1982), although those of Tropirhinus novemdecimpunctatus sec. O'Brien and Wibmer (1982) are similarly globular (see Chevrolat 1877; in particular plate IV, figure 4 therein). Lastly, Tropirhinus palpebratus [FZ2017] shows a smaller, only anteriorly extending pronotal sulcus, in contrast with a larger and more posteriorly extending pronotal impression that is flanked laterally by obtuse, rounded elevations, as present in other members of Tropirhinus [FZ2017]. Members of Pachnaeus sec. O'Brien and Wibmer (1982) have a wider rostrum and lack the posterior elytral projections, whereas those of Tetrabothynus sec. O'Brien and Wibmer (1982) have a postocular head constriction. Other close relatives (see Franz 2012) have distinctly different pronotal and elytral sculpture and coloration patterns; e.g. Compsoricus sec. Franz (2012) has large longitudinal carinae and Exophthalmus quindecimpunctatus sec. Franz (2012) has green metallic scales interspersed with distinct black maculae.

The epithet - "eyelid, wink" (Brown 1956) - refers to the combination of the postocular lobe and the setal patch located ventral thereof - a set of traits that uniquely corresponds to Tropirhinus palpebratus [FZ2017] in relation to close relatives.

Tropirhinus palpebratus [FZ2017] is known only from the examined Dominican amber inclusion ("USNM505319"; see Material) of the Burdigalian time period. The specific mine of origin for this inclusion is unknown.

Unknown.

Female - habitus (Fig. 3). Length 9.1 mm, width 3.8 mm; shape in dorsal view oval to elongate, length/width ratio 2.4, widest near mid region of elytra; shape in lateral view elongate to pyriform. Integument uniformly dark brown to black; surface punctate, though with larger, irregularly spaced and shaped concavities on pronotum; integument covered with setae and scales, most dense on elytra, less so on head (including rostrum) and legs; scales completely covering elytra, small, subcircular, overlapping, apparently predominatly pale in color though interspersed with green metallic scales, particularly along lateral regions of elytra and on the head and legs; setae short and linear, pale yellow, densely and regularly arranged, particularly on pronotum and elytra where setae are recurvate and directed mesally to posteriorly, setae longer, fine, aurate, and suberect on legs.

Mouthparts. Mandibles equilateral, asymmetrical, with 6-10 fine setae of variable length; mandibular scar positioned apicolaterally, projected. Maxillae with maxillary palps 3-segmented. Labium with prementum cordate, equilateral; labial palps apparently 3-segmented.

Rostrum. Length 1.45 mm, rostral/pronotal length ratio 0.75, rostral length/width ratio 1.8. Rostrum in dorsal view elongate, dorsolateral margins subparallel and weakly arcuate along posterior 2/3, expanded along anterior 1/3, anterodorsal margin weakly emarginate; epistoma with nasal plate (see Vaurie 1963) slightly angled in relation to posterior rostrum region, weakly depressed, V-shaped carina weakly projected, and posteriad thereof (at transition of nasal plate and remainder of rostrum) with a slight, transverse carina which is mesally interruped and posteriorly connected to a median, longitudinal carina (see Franz 2012: character 14[1]); dorsal surface tricarinate, with 1 stronger median and 2 weaker dorsolateral carinae, each carina narrowly rounded, glabrate, extending posteriorly to mid point between eyes, the paired dorsolateral carinae anteriorly slightly diverging (see Franz 2012: character 17[1]). Rostrum in lateral view sightly arcuate, width similar throughout; scrobe lateral, subrectate, passing over ventral region of eye and terminating near mid point of eye where the scrobe is continuous with the occipital suture (see Lyal 1995 and Franz 2012: character 28[1]); antennal insertion near anterior 1/4. Rostrum in ventral view with a long, triangular impression (see Franz 2012: character 29[2]). Antennae 11-segmented, covered with sparse metallic scales and fine, recurved setae; scape slender, slightly arcuate, extending to posterior margin of eye, and passing over eye (in idealized position); funicle 7-segmented, funicular antennomeres elongate, weakly clavate, increasingly shorter towards apex; club 3-segmented, elongate, similar in length to funicular antennomeres V-VII.

Head. Eyes large, globular (strongly roundly protruded), dorsolaterally positioned, separated by distance slightly shorter than anterior-to-posterior length of each eye; outline in lateral view elliptical (horizontally more extended), ventral margin less rounded.

Thorax. Pronotum in dorsal view equilateral, length/width ratio 1.5 (though challenging to observe due to the fossil's position in an inclusion with limited viewing access of the pronotum), pronotal/elytral length ratio 0.5; widest near posterior margin, lateral margins continously rounded and posteriorly diverging; surface punctate to foveate, with irregularly spaced and shaped concavities, ranging from subcircular to elongate to arcuate (see Franz 2012: character 45[1]), though no scales apparent therein; median sulcus absent. Pronotum in lateral view equilateral; anterolateral margins straight (without postocular lobe), presence of postocular vibrissae not unambiguously observable. Scutellum exposed by elytra, small, subcircular. Epipleura with mesepisternum triangular; mesepimeron dorsally oblique truncate; metepisternum narrowly linear, anteriorly widened; metepimeron entirely covered by elytron. Prothoracic ventrite with anterior transverse sulcus; procoxal cavities positioned near mid point, contiguous. Mesothoracic ventrite challenging to observe, though mesocoxal cavitities apparently narrowly separated. Metathoracic ventrite with median sulcus present as a large, transverse fovea positioned anteriad of posterior margin; metacoxal cavities separated by distance similar to width of each metacoxal cavity. Metendosternite not observed.

Legs. Prothoracic and metathoracic legs each slightly longer than mesothoracic legs (mesofemora shortest in comparison), highly similar to those of Diaprepes abbreviatus sec. Franz (2010a). Profemoral/pronotal length ratio 1.05; profemur ventrally inermous. Protibial/profemoral length ratio 1.4; protibia apically angulate-arcuate, width similar throughout, apex slightly expanded; anteromesal margin with 8-12 small, narrowly triangular teeth, each tooth distally with 1 brownish, spiniform seta; protibial apex weakly rounded, setal comb absent, promucro similar in length to protarsal claw; protarsus with tarsomere I slightly longer than II which is similar in length to III, yet I shorter than V; protarsal claws paired, separate, simple. Mesotibiae and metatibiae nearly straight, apically slightly expanded and weakly rounded; metatibial apex with an elliptical outer bevel ("corbel enclosed"; see Thompson 1992).

Elytra. Length/width ratio 1.5; widest near mid region; anterior margins jointly wider than posterior margin of pronotum (though challenging to observe along a crack in the amber inclusion), slightly sinuate; humeri present, rounded; lateral margins subparallel along anterior 1/2, therafter gradually and roundly converging, posterior edges narrow, actue, though not projected. Elytra in lateral view with dorsal outline weakly convex along anterior 3/4, thereafter (along posterior 1/4) with weakly angulate, straight declivity. Elytra with striae I-IX complete, stria X only apparent along anterior and posterior 1/3; striae slightly narrower than intervals; punctures separated by distance shorter than or similar to width of each puncture; intervals slightly and roundly elevated, no carinae apparent (as, e.g., in Diaprepes abbreviatus Franz 2010a); pale-colored and interspersed green metallic scales (the latter particularly in lateral regions) covering elytra densely and homogenously, with no maculae apperent; with short, linear to spatulae, pale yellow to light brown, regularly spaced, mesally to posteriorly directed setae throughout elytral surface.

Wings. Present, and visible in part (apical 1/2) since the specimen had its wings extended prior to its preservation in amber; veins RP1 and RP2 apparent (see Oberprieler et al. 2014), and interjacently with a large, longitudinal, brown macula.

Abdomen. Venter with segments III and IV jointed (see Thompson 1992 for segment homology), III slightly longer than IV, and separated by sinuate suture; V-VII separate; V and VI jointly as long as IV, posterior margins elevated-projected; VII slightly longer than III, triangular, posteriorly narrowly rounded, subacute (see Franz 2012: character 86[1]); all segments densely covered with whitish, appressed scales (absent laterally in III-V), VII posteriorly with long, suberect, aurate setae. Pygidium posteriorly narrowly converging, subacute, covered by elytra.

Terminalia. Not externally visible; however, the triangular, posteriorly narrowly projected ventral segment VII is indicative of this specimen being female (see Franz 2010a, Franz 2012).

Male. Unknown.

Generic placement. Diaprepes anticus [FZ2017] shares with (e.g.) Diaprepes maugei (Boheman 1840) sec. Franz 2012 numerous phylogenetically informative traits inferred in Franz 2012 that substantiate this generic placement (see also Tables 1, 2, 3, 4, 5, 6). They include: 14(1): rostrum with epistoma (see Vaurie 1963) posteriorly separated from remainder of rostrum by a slight transverse carina, which is mesally interrupted and posteriorly connected to a median longitudinal carina; 16(1): rostrum dorsally mono- or tricarinate; 17(1) rostrum tricarinate, with a characteristic combination of one median carina and two (dorso-) lateral, apically slightly diverging carinae, each carina narrow, moderately sharp; 23(0): scrobe (of antenna) passing over eye in lateral profile; 28(1): rostrum on ventral side with occipital sutures (see Lyal 1995) posteriorly moderately wide and deep, oriented horizontally, and extending to ventral midpoint of eye; 29(2): rostrum on ventral side with long, narrowly triangular impression flanked by hypostomal-labial sutures (see Lyal 1995); 45(1): pronotum in dorsal profile with small, shallow, densely arranged, irregularly shaped and spaced concavities, covered with varying numbers of small, elongate, appressed scales; 58(2): metatibial apex with an outer bevel ("corbel enclosed"; see Thompson 1992); 64(0): elytra in dorsal provide with strial intervals not roundly elevated; 83(0): wings fully developed; and 86(1): female with sternum VII of venter in ventral profile posteriorly sharply and narrowly triangular, lateral margins straight. This combination of character states is shared only between Diaprepes anticus [FZ2017], Diaprepes famelicus (Olivier 1790) sec. Franz 2012, Diaprepes marginicollis Chevrolat 1880 sec. Franz 2012, and Diaprepes maugei sec. Franz 2012 as coded in that latter analysis, and therfore justifies the placement of Diaprepes anticus [FZ2017] within Diaprepes [FZ2017].

Franz 2012 assigned Diaprepes sec. Franz 2012 to the tribe Eustylini Lacordaire 1863 [non-focal], and this placement is not under taxonomic scrutiny here.

Differential diagnosis. Diaprepes anticus [FZ2017], in addition to being extinct and recorded from Dominican amber, is readily distinguished from extant members of Diaprepes [FZ2017] by the absence of postocular vibrissae (character 48[0]), the absence of variously extended, rounded, and glabrate elytra carinae (character 64[0]), and the absence of striped elytral regions with intermixed appressed and suberect scales (character 79[0]; all characters and states according to Franz 2012). Diaprepes anticus [FZ2017] most closely resembles Diaprepes famelicus sec. Franz 2012 and in particular Diaprepes maugei sec. Franz 2012 with which is shares metallic scale coloration (see also O'Brien and Kovarik 2001). Nevertheless, the pronotal and elytral scale and setal patterns of Diaprepes anticus [FZ2017] are diagnostic by virtue of combining densely and homogenously arranged pale scales with interspersed metallic scales and abundant, short, spatulate setae. The apparent transverse rostral carina more roundly protruded eyes, and less posteriorly acute female ventral segment VII further distinguish Diaprepes anticus [FZ2017] from the aforementioned and presumed close relatives.

The epithet - "in front, foremost" (Brown 1956) - refers to Diaprepes anticus [FZ2017] being oldest documented member of Diaprepes [FZ2017] .

Diaprepes anticus [FZ2017] is known only from the examined Dominican amber inclusion ("USNM505325"; see Material) of the Burdigalian time period. The specific mine of origin for this inclusion is unknown.

Unknown.