Groehnizomus, DE FRANCESCO MAGNUSSEN &, 2022

Magnussen, Ilian De Francesco, Müller, Sandro P., Hammel, Jörg U., Kotthoff, Ulrich & Harms, Danilo, 2022, Diversity of schizomids (Arachnida: Schizomida) revealed by new fossil genera and species from mid-Cretaceous Burmese amber with implications for a Gondwanan origin of the Burma Terrane, Zoological Journal of the Linnean Society 196, pp. 792-844 : 810

† GROEHNIZOMUS DE FRANCESCO MAGNUSSEN &

S.P. MÜLLER GEN. NOV.

( FIGS 12–23 )

Zoobank registration: urn:lsid:zoobank.org:act:64D36CD9-3AEE-4899-8DFA-5F6BAB6415F7

Type species: † Groehnizomus oculiferans De Francesco Magnussen & S.P. Müller sp. nov.

Remarks

Specimens of this genus show asymmetrical tarsal spurs and also differ from species of the Protoschizomidae by lack of the pair of setae at the base of the anterior process and the presence of a distinct stalk at the male flagellum. They also differ from members of Megaschizominae by having a smaller body size, lack of eight or nine setae on their anterior process and the presence of only one pair of setae on the tergites II– VII. Therefore, they are clearly members of subfamily Hubbardiinae . The specimens cannot be assigned to any extant genus because of their combination of characters.

Diagnosis

† Groehnizomus differs from all other hubbardiid genera through a combination of characters: anterior process with one seta followed by a pair of setae; propeltidium with a single seta followed by four pairs of setae (equivocal in † G. oculiferans ); corneate eyes present; metapeltidium divided; body without clavate setae; pedipalp trochanter with a mesal spur; anterodorsal margin of femur of leg IV produced at an angle of ~90°; tergite II with one pair of setae; tergites X–XII not elongated; tergite XII with posterodorsal process; male flagellum dorsoventrally flattened.

Etymology

The genus name is a patronym for Carsten Gröhn, who donated the specimen, combined with the suffix -zomus, which is commonly used for schizomids. It is masculine in gender.

Comparisons

† Groehnizomus has similarities to Oculozomus Reddell & Cokendolpher, 1995 from Sumatra, but Oculozomus has a larger body size range of 3.5–6.0 mm. Both genera also differ in the shape of the male flagellum (round-bulbous in Oculozomus ; subrhomboidal in † Groehnizomus ). In Oculozomus , the femur of leg IV is <2.1 times longer than deep, but ~2.75–3.40 times longer than deep in † Groehnizomus . There are also similarities to † Mesozomus , but this genus lacks a posterodorsal process, has a single median seta followed by only three pairs of setae on the propeltidium and has an oblong-oval male flagellum. For comparison with Recent genera, see the Supporting Information ( Table S1).

Note

In † G. oculiferans , the setation of the propeltidium is equivocal. Therefore, this character is not included in the comparison.

Figures

Figure 12. Specimen GPIH05049, †Groehnizomus oculiferans sp. nov., holotype. A, specimen in dorsal view, photograph. B, same, interpretative drawing. C, specimen in ventral view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 1 mm.

Figure 13. Specimen GPIH05049, †Groehnizomus oculiferans sp. nov., holotype. A, specimen in dorsal view, threedimensional (3D) model. B, specimen in ventral view, 3D model. C, specimen in left lateral view, 3D model. D, specimen in right lateral view, 3D model. See Material and methods for explanation of abbreviations. Scale bar: 1 mm.

Figure 14. Specimen GPIH05049, †Groehnizomus oculiferans sp. nov., holotype, details. A, propeltidium in dorsal view, photograph. B, same, interpretative drawing. C, metapeltidium in dorsal view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm (A, B); 0.25 mm (C, D).

Figure 15. Specimen GPIH05049, †Groehnizomus oculiferans sp. nov., holotype, morphological details. A, left pedipalp in ectal view, photograph. B, same, interpretative drawing. C, left pedipalp in ectal view, three-dimensional (3D) model. D, right pedipalp in ectal view, 3D model. E, pedipalps viewed from diagonally above, 3D model. F, pedipalps in frontal view, 3D model. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm.

Figure 16. Specimen GPIH05049, †Groehnizomus oculiferans sp. nov., holotype, morphological details. A, flagellum in dorsal view, photograph. B, same, interpretative drawing. C, flagellum in ventral view, photograph. D, same, interpretative drawing. E, flagellum in dorsal view, three-dimensional (3D) model. F, flagellum in ventral view, 3D model. G, flagellum in lateral view, 3D model. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm (A–D); 0.25 mm (E–G).

Figure 17. Specimen GPIH05055, †Groehnizomus oculiferans sp. nov., paratype. A, specimen in dorsal view, photograph. B, same, interpretative drawing. C, specimen in ventral view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 1 mm.

Figure 18. Specimen GPIH05055, †Groehnizomus oculiferans sp. nov., paratype, details. A, left pedipalp in ectal view, photograph. B, same, interpretative drawing. See Material and methods for explanation of abbreviations.Scale bars: 0.5mm.

Figure 19. Specimen GPIH05055, †Groehnizomus oculiferans sp. nov., paratype, details. A, flagellum in dorsal view, photograph. B, same, interpretative drawing. C, flagellum in ventral view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm.

Figure 20. Specimen GPIH04891, †Groehnizomus rodrigoi, sp. nov., holotype. A, specimen in dorsal view, photograph. B, same, interpretative drawing. C, specimen in ventral view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 1 mm.

Figure 21. Specimen GPIH04891, †Groehnizomus rodrigoi sp. nov., holotype, details. A, metapeltidium in dorsal view, photograph. B, same, interpretative drawing. C, propeltidium in dorsal view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm.

Figure 22. Specimen GPIH04891, †Groehnizomus rodrigoi sp. nov., holotype, details. A, left pedipalp in ectal view, photograph.B, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5mm.

Figure 23. Specimen GPIH04891, †Groehnizomus rodrigoi, sp. nov., holotype, details. A, flagellum in dorsal view, photograph. B, same, interpretative drawing. C, flagellum in ventral view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm.