Cercis usnadzei Y.X.Lin & W.O.Wong, 2015

Lin, Yan-Xiang & Wong, William Oki, 2015, Cercis usnadzei, a new replacement name for Cercis kryshtofovichii Usnadze (fossil Fabaceae), Phytotaxa 224 (1), pp. 96-99 : 96-98

publication ID	https://doi.org/ 10.11646/phytotaxa.224.1.7
persistent identifier	https://treatment.plazi.org/id/03EBBB18-466B-5931-00E9-FA54FB1E98BE
treatment provided by	Felipe
scientific name	Cercis usnadzei Y.X.Lin & W.O.Wong
status	nom. nov.

Treatment

Cercis usnadzei Y.X.Lin & W.O.Wong , nom. nov. ( Fig. 1A–C View FIGURE 1 )

Replaced synonym:— Cercis kryshtofovichii Usnadze in Bot. Zhurn. 56: 970 (leaf). 1971 [non Cercis kryshtofovichii Kornilova in the early Miocene flora of Kushuk, 59, pl. 6, figs. 6–10, pl. 24, figs. 1–5 (fruits). 1960]; Stephyrtza in the early Sarmatian flora of Bursuk, 104, pl. 8, fig. 3, pl. 19, fig. 4 (leaves). 1974 ( Fig. 1C View FIGURE 1 herein).

Homotypic synonym:— Cercis turgaica Usnadze in Komarova, Sbornik Pamjati A.N.Kryshtofovicha, 226, pl. 6, fig. 6, text-fig. 2 (leaf). 1957 [non Cercis turgaica Usnadze ex Kiritchkova in Mater . Hist. Faun. Fl. Kazakhstan 1: 148, pl. 3, fig. 1 (leaf). 1955]; Takhtajan et al. in Orlov, Osnovy Paleontologii 15: 706, pl. 28, fig. 2 (leaf). 1963; Kryshtofovich & Baikovskaya in Sarmatian flora of Krynka, 86, pl. 22, fig. 14, text-fig. 32 (leaf) [non pl. 19, fig. 10, pl. 21, fig. 6, text-fig. 33 (fruits), pl. 39, fig. 2 (leaf)]. 1965 ( Fig. 1B View FIGURE 1 herein); Rajushkina in Mater . Hist. Faun. Fl. Kazakhstan 8: 144, fig. 5g, fig. 6a, b (leaves). 1982.

Etymology:—The specific epithet is dedicated to M.D.Usnadze (Geological Institute, the Academy of Sciences of the Georgian SSR, Tbilisi) who first described this leaf fossil. The English spelling of M.D.Usnadze (М.Д.УЗНаДЗЕ) followed Takhtajan (1974: 178).

Type:— KAZAKHSTAN. Sarybulak: late Oligocene, the eastern portion of the Altyn-Shokysu Plateau in the far eastern part of Mount Saryoba (Sary-Oba, Saroba), No.14/39 (holotype), collected by V. A.Vakhrameev ( Fig. 1 A View FIGURE 1 ).

Repository:—Central Scientific Research Geological Exploration Museum ( CNIGR Museum), St. Petersburg, Russia.

Other localities:—Kusto, Zajsan depression, late Oligocene, Kazakhstan ( Rajushkina 1982); the right bank of the Krynka River, middle Miocene, Ukraine ( Kryshtofovich & Baikovskaya 1965); Bursuk, middle Miocene, Moldova ( Stephyrtza 1974).

Emended description:—Simple leaves. The petiole not preserved, or partially preserved, sometimes bearing a tiny circular impression at the base of the mid-vein in the lamina. Such an impression usually resulted from the degradation of an upper pulvinus cushion at the leaf base. The leaf lamina, grossly symmetrical, ovate, wide ovate or suborbicular, 3.3–9.0 cm long and 3.4–10.0 cm wide. The base shallowly to deeply cordate. The apex acute or shortly acuminate. The margin entire. The texture apparently chartaceous. Primary veins basal actinodromous, 7–9 in number. The mid-vein straight, stout, reaching the leaf apex. The outermost lateral primary veins thin and short, extending along the lower margin of the lamina. The innermost lateral primary veins thick and long, forming a ca. 30–60° angle with the mid-vein and arching upward along the leaf margin. Lateral primary veins usually curved, connecting with adjacent secondary veins to form a series of arches and loops. Secondary veins simple brochidodromous, 2–4 pairs on the mid-vein, departing at ca. 30°–70° angle, as well as 2–6 in number on the exmedial side of lateral primary veins, diverging at ca. 30°–90° angle and forming compound agrophic veins. Tertiary veins alternate and opposite, percurrent or ramified, convex or sinuous. Marginal ultimate veins looped and fimbriate. Other higher-order veins invisible. Cuticles unavailable.

Discussion:— Cercis turgaica Usnadze was instituted only on the basis of one leaf impression ( Usnadze 1957; Fig. 1A View FIGURE 1 ), but its original circumscription was enlarged by Kryshtofovich & Baikovskaya (1965) who also attributed some fossil fruits to this species. These fruits, i.e., Kryshtofovich & Baikovskaya (1965: pl. 19, fig. 10, pl. 21, fig. 6, text-fig. 33) from the middle Miocene of Krynka, eastern Ukraine do not show any organic connections with the leaf, i.e., Kryshtofovich & Baikovskaya (1965: pl. 22, fig. 14, text-fig. 32), so the fossil fruits require a different name. In addition, another leaf, i.e., Kryshtofovich & Baikovskaya (1965: pl. 39, fig. 2) clearly bears the pinnate venation, so it does not belong to Cercis commonly having the basal actinodromous venation. Hence, Cercis usnadzei as a new replacement name for C. kryshtofovichii Usnadze , which in turn substituted C. turgaica Usnadze , should be only used for the leaf fossils. It has been discovered from the late Oligocene to middle Miocene of Sarybulak, Kusto ( Kazakhstan), Krynka ( Ukraine), and Bursuk ( Moldova).

Leaf fossils of Cercis Linnaeus (1753: 374) have been reported from the Late Cretaceous and Cenozoic of the world, but the overwhelming majority have been rejected, questioned, revised, or in need of confirmation by reinvestigation of the original materials and discovery of better preserved materials ( Owens et al. 1998, Wang 2012, Wang et al. 2014). Here are some reliable records. C. parvifolia Lesquereux was described from the late Eocene Florissant Formation of Colorado and John Day Formation of Oregon, western USA ( Jia & Manchester 2014; Fig. 1D View FIGURE 1 ), which is different from C. usnadzei in having smaller leaves (1.5–4 × 1.5–4 cm in size) usually with round or truncate bases. C. antiqua Saporta from the late Oligocene of southern France bears obovate-orbicular leaf laminae with rounded or cuneate bases ( Saporta 1862), which are evidently different from C. usnadzei . C. miochinensis Hu & Chaney from the middle Miocene of China and Japan ( Hu & Chaney 1938, Tanai & Suzuki 1972, Ina 1981, Wang 2012; Fig. 1E View FIGURE 1 ) is very similar to C. usnadzei , but it usually bears straight primary veins (especially in the middle-lower part of laminae) and broadly cordate leaf bases. C. usnadzei is very similar to an extant species C. chinensis Bunge ( Fig. 1F View FIGURE 1 ), but it usually bears more secondary veins on the exmedial side of lateral primary veins.