Dryolimnas Sharpe, 1893

Hume, Julian Pender, 2019, Systematics, morphology and ecology of rails (Aves: Rallidae) of the Mascarene Islands, with one new species, Zootaxa 4626 (1), pp. 1-107 : 38-39

Genus Dryolimnas Sharpe, 1893

Dryolimnas Sharpe, 1893, p.26 = Rallus cuvieri Pucheran, 1845, p.279 . Type by original designation

Etymology: From Greek drus, tree, and Modern Latin, limnas rail (> Gr. limnas of the marsh> limnç marsh)

Diagnosis of relevant skeletal anatomy: Rostrum ( Fig. 25 ), short and straight; in dorsal view, os nasale narrower than os premaxillare; in lateral view, narial opening long and approximately 45% of bill length; foramina neurovascularia small and few in number; in ventral view, os premaxillare deeply excavated.

Humerus ( Fig. 26 ): in caudal view, shaft dorsoventrally curved; caput humeri bulbous; tuberculum ventrale prominent and directed caudad; incisura capitis deeply excavated; tuberculum dorsale prominent and directed laterad; crista deltopectoralis short and weakly triangular; fossa pneumotricipitalis deeply excavated; crista bicipitalis terminates in sharp angle to shaft; margo caudalis raised and extends distally to mid-shaft; processus flexorius extends further distad than condylus dorsalis; indistinct processus supracondylaris dorsalis; fossa olecrani deeply excavated; in cranial view, sulcus ligamentosa transversus shallow; sulcus n. coracobrachialis indistinct; fossa m. brachialis deeply excavated; epicondylus ventralis prominent.

Pelvis ( Fig. 27 ): in dorsal aspect, ala preacetabularis ilii expanded proximally, lateral edges angular; crista spinosa synsacri forms a single distinct ridge; proximal end of extremitas cranialis synsacri extends further craniad than crista iliaca dorsalis; foramina intertransversariae large and oval-shaped; in lateral view, ala preacetabularis deep with strongly arched crista iliaca dorsalis.

Femur ( Fig. 28 ): proximal and distal ends incurved both posteriorly and internally, exhibiting two curvatures in two different planes; in cranial aspect, crista trochanteris forms distinct, dorsally facing ridge; in caudal aspect, deeply excavated medial to facies articularis acetabularis; condylus medialis and condylus lateralis connected with distinct ridge.

Tibiotarsus ( Fig. 29 ): robust, with wide and deep proximal and distal ends; in cranial aspect, crista cnemialis distinct, directed cranio-dorsad; crista fibularis long and triangular distally; pons supratendineus wide; canalis extensorius deflected mediad; condylus lateralis larger than condylus medialis; sulcus m. fibularis deeply excavated; in caudal aspect, trochlea cartilaginis tibialis deeply excavated.

Tarsometatarsus ( Fig. 30 ): cotyla lateralis lower than cotyla medialis; retinaculum extensorium ossified; trochlea metatarsi II shorter than other trochlea and directed strongly plantad; in dorsal aspect, trochlea metatarsi III largest with a deep sulcus extending onto facies dorsalis; foramen vasculare distale large and oval-shaped; on proximal end, crista medialis flexoris digitorum longus present; sulci for tendon of musculus flexor perforatus digiti II and musculus flexor hallucis longus present.

Figures

FIGURE 25. Comparison of crania and rostra of Dryolimnas cuvieri with D. chekei nov.sp., lateral view (left), dorsal view (right). A., B. NHMUK 1882.2.28.2 Dryolimnas c. cuvieri u/s; C., D. UMZC 593.B u/s, I. UMZC 593.B u/s; †D. chekei u/s; E., F. NHMUK S/1989.38.1 D. c. aldabranus ♂; NHMUK 1910.4.8.1 G., H. †D. c. abbotti u/s. Scale bar = 10 mm.

FIGURE 26. Comparison of humeri of Dryolimnas cuvieri and Gallinula chloropus with D. chekei nov. sp., caudal aspect (above), cranial aspect (below). A. NHMUK S/1989.38.1 Dryolimnas c. aldabranus ♂; B. NHMUK 1910.4.8.1 †D. c. abbotti u/s; C. UMZC 300AA4 †D. chekei u/s; D. NHMUK 1882.2.28.2 D. c. cuvieri u/s; E. NHMUK S/1977.23.1 Gallinula chloropus u/s. Scale bar = 10 mm.

FIGURE 27. Comparison of pelves of Dryolimnas cuvieri and Gallinula chloropus with D. chekei nov. sp., dorsal view. A. NHMUK S/1977.23.1 Gallinula chloropus u/s. B. NHMUK S/1989.38.1 Dryolimnas c. aldabranus ♂; C. UMZC 300AA5 †D. chekei u/s; D. NHMUK 1882.2.28.2 D. c. cuvieri u/s; E. NHMUK 1910.4.8.1 †D. c. abbotti u/s. Scale bar = 10 mm.

FIGURE 28. Comparison of femora of Dryolimnas cuvieri with D. chekei nov. sp., caudal aspect. A. UMZC 300AA3 †Dryolimnas chekei u/s; B. NHMUK 1910.4.8.1 †D. c. abbotti u/s; C. NHMUK S/1989.38.1 D. c. aldabranus ♂; D. NHMUK 1882.2.28.2 D. c. cuvieri u/s. Scale bar = 10 mm.

FIGURE 29. Comparison of tibiotarsi of Dryolimnas cuvieri and Gallinula chloropus with D. chekei nov. sp., cranial aspect. A. C. NHMUK S/1977.23.1 Gallinula chloropus u/s. B. UMZC 300AA4 u/s, D. UMZC 300AA3 †Dryolimnas chekei u/s; E. NHMUK 1882.2.28.2 D. c. cuvieri u/s; F. NHMUK S/1989.38.1 D. c. aldabranus ♂; G. NHMUK 1910.4.8.1 †D. c. abbotti u/s. Scale bar = 10 mm.

FIGURE 30. Comparison of tarsometatarsi of Dryolimnas cuvieri and Gallinula chloropus with D. chekei nov. sp., (above) dor- sal aspect, (below) plantar aspect.A. UMZC 593B u/s, B. UMZC 300AA5 †Dryolimnas chekei u/s; C. NHMUK 1897.5.10.47 D. c. cuvieri u/s; D. NHMUK 1910.4.8.1 †D. c. abbotti u/s; E. NHMUK S/1989.38.1 D. c. aldabranus ♂; F. NHMUK S/1977.23.1 Gallinula chloropus u/s. Scale bar = 10 mm.