Cretaceozomus, De Francesco Magnussen, 2022, 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 : 802-806

† CRETACEOZOMUS ANGUSTOCAUDATUS DE

FRANCESCO MAGNUSSEN SP. NOV.

( FIGS 6–8 )

Zoobank registration: urn:lsid:zoobank.org:act:7B08CF32-2C1F-4507-BA94-C87B97CFCCFB

Type material: Holotype (F i g. 6A –D), a d u l t homeomorphic ♂, collection no. GPIH04896 ; ex collection Patrick Müller (no. BUB06 ).

Diagnosis

† Cretaceozomus angustocaudatus differs from † Cretaceozomus robustus by its thick pedipalps, femur of leg IV 3.1 times longer than deep and flagellum slender and oblong.

Etymology

The specific epithet is derived from the Latin words angustus, narrow, and cauda, tail, referring to the shape of the male flagellum. It is masculine in gender.

Description

Total length from anterior dorsal process to base of the flagellum ~ 3 mm.

Colour (in amber): Dorsal side dark brown; patella, tibia and tarsus of the legs II–IV golden to light brown; ventral side golden brown; flagellum and pedipalps dark brown, original colouring equivocal.

Prosoma ( Fig. 7A, B ): Length 1.36 mm; propeltidium length 1.12 mm, width 0.56 mm. Anterior process long and broad, length 0.18 mm; setation: two setae next to each other followed by a single median seta. Propeltidium setation: four pairs of setae, first pair aborted, tubercles visible, following three pairs left ones visible, right ones aborted. Corneate eyes present, clearly elevated above the surface of the propeltidium. Mesopeltidium width (left) 0.2 mm. Metapeltidium not divided ( Fig. 8A, B ), length 0.32 mm, width 0.64 mm. Anterior sternum with> 10 + 2 sternapophysial setae, length 0.31 mm, width 0.26 mm. Posterior sternum with seven setae, length 0.19 mm, width 0.25 mm.

Chelicerae: Setation of the mesal side of chelicerae not visible, except for G6-1.

Pedipalps: Robust, without armature except for a mesal spur on trochanter ( Fig. 7C, D ); trochanter produced distally, setation: one+ mesal, five ventral, two ventroectal, one+ ectal; femur: longer than trochanter, setation: eight+ dorsal, two+ dorsomesal, two+ ectal, three + mesal, one + ventral, two + dorsoectal, t w o+ v e n t r o e c t a l; p a t e l l a: l o n g e r t h a n f e m u r, setation: one+ mesal, four+ ectal, two+ dorsomesal, two+ dorsoectal, five dorsal; tibia: shorter than patella, setation: six dorsomesal, two+ ventromesal, four+ ectal, six dorsoectal, five+ mesal, six dorsal; tarsus: setation: two+ dorsoectal, two+ dorsomesal; claw not visible.

Legs: Right leg I aborted at the end of the trochanter, left leg incomplete, tarsus missing, leg I ≥ 1.05 times longer than the body; anterodorsal margin of femur of leg IV produced at an angle of ~90°, femur of leg IV 3.1 times longer than deep, leg IV> 1.08 times longer than the total body length; leg formula presumed: 1423.

Opisthosoma: Not entirely visible, length 1.60– 1.65 mm, width 0.9 mm; segments X–XII not elongated, segments IX–XII not visible owing to overlaying debris. Abdominal tergites setation: I–IV: Dm; V: not visible; VI: Dm, Dl1; VII: Dm, Dl1; VIII: Dm, Dl1; XI–XII not visible; setation pattern: 2:2:2:2:?:4:4:4:?:?:?:?. Flagellum: slim, dorsoventrally flattened with a slender and oblong shape ( Fig. 8C, D ), length 0.27 mm, width 0.18 mm; stalk length 0.09 mm; setation: Dm1 not visible; Dm4; Dl2 paired, sitting lateral; Dl3 paired, with the left one aborted; Vm1; Vm2 paired; Vm3 paired; Vm5; Vl2 paired. Pair Vl1 absent in this species.

Further measurements: Pedipalp: trochanter 0.41 mm; femur 0.53 mm; patella 0.63 mm; tibia 0.49 mm; tarsus> 0.20 mm; claw not measurable; total length> 2.26 mm. Leg I: trochanter 0.20 mm; femur 1.09 mm; patella 1.11 mm; tibia> 0.75 mm; metatarsus not measurable; tarsus not measurable; total length> 3.15 mm. Leg II: trochanter 0.18 mm; femur 0.73 mm; patella 0.43 mm; tibia 0.51 mm; metatarsus 0.34 mm; tarsus (tarsus segments) 0.34 mm (0.12 mm; 0.08 mm; 0.14 mm); total length 2.53 mm. Leg III: trochanter 0.20 mm; femur 0.67 mm; patella 0.33 mm; tibia 0.38 mm; metatarsus 0.29 mm; tarsus (tarsus segments) 0.32 mm (0.14 mm; 0.08 mm; 0.10 mm); total length 2.19 mm. Leg IV: trochanter 0.22 mm; femur 1.09 mm; patella 0.36 mm; tibia 0.61 mm; metatarsus 0.56 mm; tarsus (tarsus segments) 0.39 mm (0.16 mm; 0.09 mm; 0.14 mm); total length 3.23 mm.

Figures

Figure 6. Specimen GPIH04896, †Cretaceozomus angustocaudatus 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 7. Specimen GPIH04896, †Cretaceozomus angustocaudatus sp. nov., holotype, details. A, prosoma in dorsal view, photograph. B, same, interpretative drawing. C, right pedipalp in ectal view, photograph. D, same, interpretative drawing. See Material and methods for explanation of abbreviations. Scale bars: 0.5 mm.

Figure 8. Specimen GPIH04896, †Cretaceozomus angustocaudatus sp. nov., holotype, details. A, metapeltidum 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: 0.25 mm (A, B); 0.5 mm (C, D).