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
Author
Magnussen, Ilian De Francesco
Author
Müller, Sandro P.
Author
Hammel, Jörg U.
Author
Kotthoff, Ulrich
Author
Harms, Danilo
text
Zoological Journal of the Linnean Society
2022
2022-05-24
196
792
844
journal article
10.1093/zoolinnean/zlac034
0024-4082
7187082
26533E9F-C53F-4051-B6B4-990E63C08C74
†
ANNAZOMUS PARVULUS
DE FRANCESCO
MAGNUSSEN
SP. NOV.
(
FIGS 3–5
)
Zoobank registration:
urn:lsid:zoobank.org:act:
9221DD2F-0C17-48AC-8904-C18E18A05F96
Type material:
Holotype
(
Fig. 3A –D
), adult homeomorphic
♂
, collection no.
GPIH
04893
; ex collection Patrick Müller (no. BUB556).
Diagnosis
Pedipalps short; flagellum shape nearly rectangular, with a bulbous elevation on the left and right dorsal side; small body size of
1.95 mm
.
Etymology
The specific epithet is Latin
parvulus
, small, referring to the small body size of the specimen. It is masculine in gender.
Description
Total length from the anterior process to the base of the flagellum
1.95 mm
.
Figure 3.
Specimen
GPIH04893
, †
Annazomus parvulus
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 4.
Specimen
GPIH04893
, †
Annazomus parvulus
sp. nov.
, holotype, details.A, metapeltidium dorsal view, photograph. B, same, interpretative drawing. C, right pedipalp in mesal 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).
Colour (in amber):
Light brown and golden; prosoma, opisthosoma, flagellum, femur IV and pedipalps slightly darker brown golden; leg I golden and translucent, original colouring equivocal.
Prosoma:
Length
0.83 mm
; propeltidium length
0.68 mm
, width
0.32 mm
. Anterior process sharply bent down, length not measurable; setation: one seta, sitting on the left side of the anterior process, no further setation visible; small round holes in the proximal part of the propeltidium prevent reconstruction of further setation, but there might have been a pair of setae with the right one now missing, definite setation remains unclear. Propeltidium setation prosoma: three pairs, first pair of setae still in place, second pair left one aborted, third pair both aborted with only left tubercle visible, right one not visible owing to a crack in the amber covering parts of the propeltidium. Corneate eyes and eyespots absent. Mesopeltidia width (right): ~
0.11 mm
, left one not visible owing to an air bubble in the amber. Metapeltidium not divided with a thin suture (
Fig. 4A, B
), length
0.2 mm
, width
0.42 mm
. Anterior sternum with 10 + 2 sternapophysial setae, length
0.24 mm
, width
0.22 mm
. Posterior sternum with six setae, length
0.12 mm
, width
0.11 mm
.
Figure 5.
Specimen
GPIH04893
, †
Annazomus parvulus
sp. nov.
, holotype, 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 based on synchrotron scan. F, flagellum in ventral view, 3D model based on X-rayscan. G, flagellum in lateral view, 3D model based on X-ray-scan. See Material and methods for explanation of abbreviations. Scale bars: 0.25 mm.
Chelicerae:
Setation of the mesal side of chelicerae not visible, except for G6-1.
Pedipalps:
Short and slim, without armature (
Fig. 4C, D
), mesal spur on trochanter not visible; trochanter setation: five ventral strong setae, two ectal, four mesal setae; femur: longer than trochanter, setation: five dorsal, three ectal, two ventroectal, three mesal; patella: shorter than femur, setation: four mesal, two ectal, four dorsomesal, two dorsoectal, three dorsal; tibia: shorter than patella, setation: three dorsomesal, three ectal, two ventroectal, two dorsoectal, five mesal; tarsus: with tarsal spurs, spur length:
0.02 mm
, setation: three ectal, four dorsoectal, four ventroectal, two dorsal, three dorsomesal, three+ ventromesal, five mesal, two+ ventral; claw: straight, slightly longer than half the length of tarsus.
Legs:
Right leg I aborted at the trochanter, left leg well preserved and complete, tarsus with six segments, leg I ~1.37 times longer than the body; anterodorsal margin of femur of leg IV produced at an angle of ~90°, femur of leg IV 2.65 times longer than deep; leg IV> 1.04 times longer than the total body length; leg formula: 1423.
Opisthosoma:
Length
1.12 mm
, width
0.42 mm
; tergites X–XII not elongated, tergite XII with a large, rectangular posterodorsal process. Abdominal tergites setation: I: Dm; II: Dm; III: Dm, left missing; IV: Dm, both missing; V: Dm, both missing; VI: Dm; VII: Dm, both missing; VIII: Dm, left missing, Dl1; IX: Dl1, Dl2; X: Dl1; XI: Dl1; XII: Dm, Dl1, setation pattern: 2:2:2:2:2:2:2:4:4:2:2:4. Flagellum: dorsoventrally flattened, rectangular with an apical tip at the posterior end, on the dorsal side with a bulbous elevation each left and right near the posterior end (
Fig. 5A–G
), length
0.17 mm
, width
0.22 mm
; stalk length ~
0.09 mm
; setation: Dm1, Dl2 paired, Dm4, Dl3 paired and nearly at the posterior end of the flagellum, Vm1, Vm2 paired, Vm3 paired, Vl1 paired, Vm5, Vl2 paired.
Further measurements:
Pedipalp: trochanter
0.16 mm
; femur
0.26 mm
; patella
0.23 mm
; tibia
0.20 mm
; tarsus
0.13 mm
; claw
0.07 mm
; total length
1.05 mm
. Leg I: trochanter
0.19 mm
; femur
0.61 mm
; patella
0.71 mm
; tibia
0.58 mm
; metatarsus
0.24 mm
; tarsus (tarsus segments)
0.34 mm
(
0.04 mm
;
0.04 mm
;
0.04 mm
;
0.04 mm
;
0.05 mm
;
0.13 mm
); total length
2.67 mm
. Leg II: t r o c h a n t e r 0.1
2 m
m; f e m u r 0.4
9 m
m; p a t e l l a
0.22 mm
; tibia
0.25 mm
; metatarsus
0.29 mm
; tarsus (tarsus segments)
0.26 mm
(
0.10 mm
;
0.06 mm
;
0.10 mm
); total length
1.63 mm
. Leg III: trochanter
0.13 mm
; femur
0.48 mm
; patella
0.17 mm
; tibia
0.19 mm
; metatarsus
0.25 mm
; tarsus (tarsus segments)
0.26 mm
(
0.12 mm
;
0.06 mm
;
0.08 mm
); total length
1.48 mm
. Leg IV: trochanter
0.19 mm
; femur
0.70 mm
; patella>
0.22 mm
; tibia>
0.29 mm
; metatarsus
0.35 mm
; tarsus (tarsus segments) 0.2
8 m
m (0.1
1 m
m; 0.0
6 m
m; 0.1
1 m
m); t o t a l length>
2.03 mm
.