Libanoxenus hammanaensis, Duy-Jacquemin & Azar, 2004

Duy-Jacquemin, Monique Nguyen & Azar, Dany, 2004, The oldest records of Polyxenida (Myriapoda, Diplopoda): new discoveries from the Cretaceous ambers of Lebanon and France, Geodiversitas 26 (4), pp. 631-641 : 635-636

publication ID	https://doi.org/ 10.5281/zenodo.4665318
persistent identifier	https://treatment.plazi.org/id/D57D87F7-FFCE-BF31-05D0-EC3AD071FDA1
treatment provided by	Felipe
scientific name	Libanoxenus hammanaensis
status	sp. nov.

Treatment

Libanoxenus hammanaensis View in CoL n. sp. ( Figs 3 View FIG ; 4 View FIG )

TYPE MATERIAL. — Holotype: adult specimen number 633, Azar collection, provisionally deposited in the MNHN.

ETYMOLOGY. — After Hammana, the type locality.

TYPE LOCALITY AND TYPE HORIZON. — Mdeirij / Hammana locality, Caza of Baabda , Mouhafazit Jabal Loubnan, Central Lebanon ; Early Cretaceous, Valanginian-Hauterivian to lower Aptian (135- 125 million years). The amber piece is mounted on a microscope slide in Canada balsam medium .

DIAGNOSIS. — As for genus.

DESCRIPTION

Adult ( Figs 3 View FIG ; 4 View FIG A-J)

The trunk of the holotype is open over all its length along the axis of symmetry, hence the tergites are not seen entirely.

Measurements. Body length = 2.50 mm; penicil length = 0.30 mm; head trichomes length = 0.10 mm; total length = 2.90 mm.

Head. Eight ocelli ( Fig. 4A View FIG ). Left antenna with eight articles ( Fig. 4A View FIG ). Length to diameter ratio of the sixth antennal article = 1.80. Only the end of one sensillum basiconicum is visible on articles VI and VII ( Fig. 4B View FIG ); some setiform sensilla are seen on article III, V, VI and VII; right antenna with four articles, the article V is broken. Labrum with numerous small setae ( Fig. 4C View FIG ). Outer right palp of gnathochilarium with 12 or 13 sensilla ( Fig. 4D View FIG ); it is more than twice as long as the diameter of the middle palp.

Trunk. The tergal trichomes (seen only on the lateral part of tergites), are short ( Fig. 4E, F View FIG ); the longer lateral trichomes of tergite reach 120 to 130 µm while in the middle of the tergite the trichomes measure 50 to 53 µm. They seem to be arranged in two rows: one anterior row with trichomes directed anteriad and one posterior row with trichomes directed caudal ( Fig. 4F View FIG ). One clearly visible seta on tarsus II ( Fig. 4G, I View FIG ), nude setae ( Fig. 4H View FIG ) observed on other article (coxa, trochanter, prefemur, femur and tibia). Telotarsus with clearly visible poste- rior lamellate process longer than claw ( Fig. 4G View FIG ). Dorsal face of telson with an anterior row including three to four visible barbate trichomes. Telson is not of Polyxenus and Propolyxenus type (latter with trichomes ended by multiple hooks: Fig. 4K View FIG ); trichomes of caudal penicil with three or four aligned hooks ( Fig. 4J View FIG ).