Batola nikolai, Vršanský, 2009

Vršanský, Peter, 2009, Albian cockroaches (Insecta, Blattida) from French amber of Archingeay, Geodiversitas 31 (1), pp. 73-98 : 76-80

publication ID	https://doi.org/ 10.5252/g2009n1a7
persistent identifier	https://treatment.plazi.org/id/754F87A2-992E-707B-FCC7-66FDC33FFCDE
treatment provided by	Marcus
scientific name	Batola nikolai
status	sp. nov.

Treatment

Batola nikolai n. sp. ( Figs 1 View FIG ; 2 View FIG ; 8-12 View FIG View FIG View FIG ; 16B, E, G, H View FIG )

TYPE MATERIAL. — Holotype: ARC-254.4, complete immature feeding on a strobillus. Paratypes:ARC-261.1, adult male wings with body, terminalia and legs; ARC-037b, a complete (4th) immature; ARC-128, body of male (?2nd) immature; ARC-138, a hind leg of a subadult or adult; ARC- 47, a complete (?1st) immature; ARC-57.2, a hind leg.

TYPE LOCALITY. — Archingeay-Les Nouillers, Charente- Maritime, SW France.

STRATIGRAPHIC HORIZON. — Lower Cretaceous, uppermost Albian, lithological subunit A1sl2 sensu Néraudeau et al. (2002).

ETYMOLOGY. — After my son Nikolaj.

DESCRIPTION

Adult male, ARC-261.1 ( Figs 2 View FIG ; 10)

Pronotum, even when unpreserved, and position of wings apparently very wide. Forewings wide (6.8/ 2.4 mm); the right forewing overlaps the left one. Coloration generally expanded, particularly in the whole posterior margin of the wing. Sc simple, curved dorsally. R with 9(L)-11(R) mostly simple branches, only apicalmost branches dichotomizing; M reduced to 2(L)-4(R) branches. CuA expanded, with 5(R)-7(L) branches, with the space for additional basalmost branch free. CuP sharply curved, five or six anal veins simple.

Hindwing concealed under forewings except for apex.

Hind legs long, coxa terminated with two series of rectangular setae ( Fig. 2D View FIG ), femur robust (2.4/ 0.8 mm) with two strong supporting ridges and with three median setae. Posterior margin with two ridges bearing 5 + 7 setae. Dorsal terminal spur comparatively short, posterior margin with short chaeta and long terminal spur; tibia 3.2 mm long with slender long spurs and long strong terminal spurs, all in four rows, and with numerous very short chaeta. Base of hind leg segments round in section, with ridge present only shortly at base. Dark coloration present in basal, median and apical parts of tibiae. Subgenital plate with margins plain, with styli multisegmented (eight or more), c. 0.8 mm long. Cerci wide, of standard appearance.

Complete (?second) immature feeding on strobillus, ARC-254.4 ( Figs 1 View FIG ; 11 View FIG )

Very robust individual.Head almost as wide (1.1 mm) as pronotum. Antenna of standard appearance, with at least 22 segments, width c. 0.04 mm. Three basal segments very long (0.67 mm), pedicel short. Each segment bearing a set of transversal ridges and five to seven subapical sensilla chaetica about as long as half segment length. Starting with the 9th segment, setae forming two rows. Segments dark basally. Maxillary palps short and thick, three terminal segments visible (0.18/0.2/ 0.22 mm).

Pro-, meso- and metanotum with apparent long marginal setae (dark coloration as in Figures 1 View FIG and 11 View FIG ). Pronotum very wide, strongly transversal (0.6/ 1.2 mm). Body wide (1.6 mm) and coloured, six undifferentiated terga visible, supragenital plate terminated with six sensilla chaetica. Cerci long and massive, with seven visible segments and long sensilla chaetica. Each segment bears a set of two strong sensilla chaeta and 2-6 extremely long sensilla chaetica.

Legs short, carinated. Fore coxae comparatively long (0.69 mm), trochanter distinct (0.25 mm), femur robust (0.84/ 0.2 mm), tibia short and thin (0.6/ 0.1 mm), tarsus very long (0.77 mm: 0.24/0.22/ 0.11/0.07/ 0.13 mm). Mid coxa shorter (0.33 mm), less distinct than the fore coxa; trochanter very large (0.33 mm) femur robust (0.8/ 0.27 mm); tibia arcuate near basis, 0.69 mm long, with numerous spurs and chaeta; tarsus very long (0.71 mm: 0.27/0.16/0.12/0.05/ 0.11 mm) with 8-10 rows of chaeta. Hind coxa large (0.36 mm), trochanter very large (0.33 mm); femur robust (0.93/ 0.31 mm) with short terminal spur; tibia long and thin (1.09/ 0.1 mm), with numerous spurs and chaeta. Tarsus long (0.85 mm) with numerous chaeta (0.36/0.24/0.07/0.05/ 0.13 mm). Overall specimen length c. 2.7 mm.

Complete (?fourth) immature, ARC-037b1

( Figs 8 View FIG -10)

Very robust individual, but body comparatively not as wide as in the preceding immature. Head comparatively smaller (1.26/ 1.47 mm) in respect to pronotum (1.4/ 2.3 mm). Eyes long and narrow, not protruding beyond the head outline. Maxillary palps comparatively slender and narrow, terminal three segments 0.63/0.47/ 0.63 mm long.

Mesonotum wider than pronotum (2.73 mm), metanotum slightly narrower (2.67 mm). Body 2.5 mm wide. Cercus length c. 1.27 mm.

Leg carination very strong. Fore coxae (1.05 mm) and femora (1.26 mm) extremely long, tibia short (1.05 mm), tarsi long (0.58/0.21/ 0.16/0.05/ 0.42 mm). Mid femur very robust (1.58/ 0.47 mm), tibia short (1.32 mm), tarsi long (0.63/0.26/0.11/0.11/ 0.37 mm). Hind femora long and robust (1.79/ 0.53 mm), tibia long (1.95 mm), tarsi very long (0.84/0.26/0.16/0.16/ 0.37 mm). Overall specimen length c. 5.6 mm.

Detached abdominal apex of male (?second) immature, ARC-128 ( Fig. 16B View FIG )

Very robust (width 1.88 mm). Cerci long (1.27mm), 8-segmented, each segment with a basal row of 5-7 very long (0.41 mm) sensilla chaetica, median row of 3 or 4 short sensilla chaetica and apical row of 5-9 short sensilla chaetica;short styli with numerous sensilla chaetica present. Apical (8th) sternum significantly prolonged medially, forming a protective sheath.

A hind leg of a subadult or adult, ARC-138R

( Fig. 16E View FIG )

Melted and damaged specimen, femoral length 1.8 mm.

Complete (?first) immature, ARC-47 (examined on a low-quality photograph)

Head very large, globular, c. 1.07 mm wide.Pronotum very short (0.43/ 0.95 mm). Body width 1.19 mm. Hind tibia 0.90 mm long. Overall length of the individual c. 2.3 mm. Coloration characteristic of Batola n. gen.

Hind leg, ARC-57.2 ( Fig. 16G, H View FIG )

Coloration not preserved. Coxa short (0.34 mm), without reticulations. Femur almost round in section (length/width 1.65/ 0.45 mm), fore and hind margins with numerous long chaeta. Terminal spur short. Ventral anterior side with a set of numerous (c. 20) sensilla chaetica, cumulated basally, posterior side with two parallel rows of very small spines. Tibia (1.65/ 0.23 mm) heavily carinated; with section round at base, elongate apically, with basal part of the posterior margin lacking spurs. Spur length c. 0.31 mm. Numerous sensilla chaetica present in both anterior and posterior sides. First tarsal segment (0.73 mm) with two sets of two rows of 10 sensilla chaetica and with very strong central longitudinal elevation, with a pair of rows of 10 sensilla chaetica; second segment (0.19 mm) with four sensilla chaetica in each row; third segment (0.10 mm) with two sensilla chaetica in each row.

REMARKS

All specimens may be included within the present taxon based on the similar habitus with unusually short and wide pronotum, and thus also wide position of forewing bases, legs basing on metrics. The standard Cretaceous assemblages consist of two related sister species of Blattulidae and the same appears to be present here.

The expanded forewing coloration is an autapomorphy, inherited from Elisama , apparent ancestor of Batola n. gen.

Surprisingly, other modified structures of Batola nikolai n. sp. are palps more slender compared to Elisama . Such palps are known also from the Hauterivian amber Blattulidae from Lebanon (Anisyutkin & Gorochov 2008). Reason for the presence of shorter palps in amber, and thus in forest dweller, is unknown. Possible explanation can be the collection of pollen as evidenced by the preservation state of the type.

Basing on three specimens of different immatures, the reconstruction of number of instars can be made for Batola nikolai n. sp. The specimen ARC-47 with the overall length 2.3 mm most likely represents the first instar, even when specimen ARC-254.4, with the overall length 2.7 mm most likely represents the second instar (see also Vršanský 2008a). Applying the Dyar’s rule of succeeding instars sizes multiplied by 1.4 validated for Mesozoic cockroaches ( Vršanský 1997), the first instar should be only c. 1.9 mm long, a size comparable to first immature stages of certain Blattulidae (unpublished) (as well as the size of the specimen ARC-47). Consequently, the third instar can be expected to be 3.5-3.8 mm long, the fourth 4.9-5.3 mm – a size comparable to the specimen no. ARC-037b; the fifth 6.9-7.4 (7.8 mm), which has a size comparable to the present adult.

The size distribution provides a strong support for a small number of instars of the Blattulidae (4-5 plus imago), analogically as in some small living cockroaches.

The nymph was apparently feeding on microstrobilus, fallen into the amber. Decaying organic piece perhaps attracted attention of cockroach, which has been buried during the consumption.

The wide body habitus of the present species is very unusual within the family, and rare in the Mesozoic imprint cockroaches in general.Nevertheless, it appears logical according to the hypothesis of the amber representing fallen drops of resin on the ground, as suggested by Perrichot (2004) and then having trapped mostly ground dwellers. This is evidenced here by melting traces being horizontal, rectangular in respect to the specimen orientation instead of longitudinal. This hypothesis appears supported also by the reduction of the pronotum in two unrelated species, allowing the free movements of head and dorsal view, necessary for detection and avoidance of larger predators. Opposite evidence is provided by free-living cockroaches such as Ectobius Stephens, 1835 , which retain wide pronotum.

The dominance of the Blattulidae is not surprising as they represent the most mass insects among small cockroaches (the smallest among the mass cockroaches).