Yprezethinus grimaldii PARKER 2022, sp. nov.
Creators: name: PARKER, JOSEPH
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Yprezethinus
Yprezethinus grimaldii

description: Yprezethinus grimaldii sp. nov.
urn:lsid:zoobank.org:act: 6657B0A8-4BF3-4A3A-88DD-F943C01A9967
Holotype. Sex unknown. Label data: “ AMBER: INDIA: Gujarat / Tadkeshwar lignite mine / Cambay Form. (Paleo-Eocene) / 21°21.400′N, 73°4.532′E / I/7-12/09 Grimaldi & Nascimbene / No. Tad-130”
“Tad-130: / 1 Coleoptera: Scydmaenidae?”
Specimen in AMNH.
Etymology. The specific name honors entomologist Dr David Grimaldi—friend, mentor, colleague and collaborator—on his 65 th birthday, and in recognition of his wide-ranging contributions to the study of fossilized insects (including pioneering the investigation of Cambay amber).
Diagnosis. As for genus.
Type locality and horizon. Cambay amber preserving Yprezethinus was collected from outcrops inside lignite mines in Gujarat state, western India, Tadkeshwar (21°21.400′N, 73°4.532′E). The horizon is estimated to be Early Ypresian (ca. 54.5 Ma; see Smith et al., 2016).
Description. Body length: ~ 0.8 mm (Fig. 1A). Body largely glabrous, with smooth, shiny integument. Body color of Tad-130 dark, almost black; antennae also dark, brown-black; other appendages somewhat dark reddish brown.
Head
Head length ~ 0.13 mm (Fig. 1A); estimated width across eyes ~ 0.18 mm. Frontal rostrum medially sulcate. Head constrictedsharplybehindeyes,narrowingtoocciput.Gular region of head strongly convex to occipital constriction. Eye with approximately 10 facets. Antennomere 1 partially obscured but appears to be cylindrical-conical, and longer than wide, similar in width to antennomere 2. Antennomere 2 spherical, ~1.3× wider than antennomere 1. Antennomeres 3–9 subequal in width but varied in length and shape (Fig. 1C). Antennomeres 3–6 subequal in length, twice as wide as long; antennomere 1 transverse obconical with distinct pedicel, 4–6 transverse cylindrical with concealed pedicels. Antennomeres 7–9 subequal in length, 1.5× as wide as long; antennomere 7 roundedcylindrical, 8 and 9 weakly obconical. Ovoid club formed by antennomeres 10 and 11 (Fig. 1C); club at maximum width 3× wider than antennomeres 3–9. Antennomere 11 approximately 1.5× as long as 10. Segments of antennal club, especially antennomere 11, decorated in long, dense sensory setae (preceding antennal segments without discernable setation) (Fig. 1C). Estimated length of antenna 0.19 mm. Maxillary palpi (Fig. 1B) with short palpomere 1 and enlarged, clavate palpomere 2. Palpomere 3 broadly triangular in lateral view, twice as long as wide and approximately two thirds palpomere 2 length, with narrow, elongate, apically globose tubercle emerging dorsally at ~2/5 palpomere length (Fig. 1B, D). Palpomere 4 rounded-conical in shape, ~0.5× palpomere 3 length, dorsally bearing narrow, elongate, apically globose tubercle similar to that emerging from palpomere 3 (Fig. 1B, D). Apex of palpomere 4 bearing prominent 5th apical pseudosegment (Fig. 1B). Estimated length of extended maxillary palpus 0.18 mm. Mandibles prominent, narrow, sickle-shaped, apparently raptorial (Fig. 1B).
Thorax
Pronotum with rounded margins, widest in apical half. Pronotum 0.14 mm long, approximate width at widest point 0.2 mm.
Abdomen
Ventral abdomen length along midline 0.29 mm (Fig. 1A). Width at widest point (along apical margin of tergite IV) 0.27 mm. Tergites and sternites largely glabrous, but basal sulcus of sternite IV with apparent patch of dense, short (possibly squamous) setae.
Legs
Femora and tibiae of all legs thickened in apical half; lacking cuticular modifications. Tibiae apically setose on ventral face, most prominent on protibia. Tarsi ventrally with sparse, long mechanosensory setae. Lengths of leg segments: profemur 0.18 mm, protibia 0.13 mm, protarsus 0.07 mm, mesofemur 0.16 mm, mesotibia 0.14 mm, mesotarsus 0.06 mm, metafemur 0.16 mm, metatibia 0.16 mm, metatarsus 0.07 mm.
Elytra
Elytral length along margin 0.23 mm (Fig. 1A). Elytra apparently glabrous.
description: Published as part of PARKER, JOSEPH, 2022, Transitional morphology and Afrotropical affinity of a bythinoplectine rove beetle from the early Eocene of India (Coleoptera: Staphylinidae: Pselaphinae), pp. 452-460 in Palaeoentomology 5 (5) on pages 456-457, DOI: 10.11646/palaeoentomology.5.5.6, http://zenodo.org/record/7333729