Paleopanax puryearensis, Na & Blanchard & Wang, 2019

Na, Yuling, Blanchard, Jane & Wang, Hongshan, 2019, Fruits, seeds and flowers from the Puryear clay pit (middle Eocene Cockfield Formation), western Tennessee, USA, Palaeontologia Electronica (a 49) 23 (3), pp. 1-57 : 26-27

Paleopanax puryearensis sp. nov.

Figure 31

Diagnosis. Fruit about 1 cm in diameter, orbicular, indehiscent, with two persistent styles, an epigynous disc, and a long pedicel; carpels two, Dshaped.

Description. Laterally compressed orbicular fruit ca. 1.2 cm wide and 1 cm long, indehiscent. Two persistent styles present, ca. 2 mm long, apex recurved. Epigynous disc present, ca. 3 mm in diameter. Pedicel ca. 1.1 cm long and 1 mm wide. Carpel D-shaped in face view, ca. 8 mm long and 5 mm wide; attached ventrally to the central fruit axis by its straight margin; dorsal margin convex. Mesocarp 0.5–1 mm thick.

Holotype. Designated here. UF15820-053151 .

Paratype. UF15820-59481 , 59481 ’.

Number of specimens examined. 2. UF 15820- 053151, 59481.

Species epithet etymology. The species name refers to its occurrence at the Puryear locality, Tennessee.

Remarks. The presence of two persistent styles, two carpels, and epigynous disc is consistent with the description of the type species, Paleopanax oregonensis , and suggests this fossil genus’ affinity with the modern family Araliaceae .

Manchester et al. (2015, p. 350, figure 18 A) illustrated this specimen in discussing the fossil record of the Araliaceae , but they did not provide a description. We here formally establish a new species for this specimen. The diagnostic characters of the new species are consistent with those of the fruits from the middle Eocene Nut Beds Flora, Clarno Formation , Oregon (Manchester, 1994, pp. 38–39, pl. 7, figures 3–4) and late early Eocene Bolden locality, Tallahatta Formation , Mississippi ( Blanchard et al., 2016, p. 29, figure 24). However, the Puryear specimen is about two times larger than the fruits from Oregon and Mississippi.

Petrified wood with possible affinity to Araliaceae was reported by Wheeler and Manchester (2014) from the Clarno Formation.

Leaves belonging to the family Araliaceae , i.e., Dendropanax eocenensis Dilcher and Dolph , was reported from other Claiborne localities (Dilcher and Dolph, 1970). These leaves are also present at the Puryear locality. However, the relationship between these araliaceous leaves and fruits are unknown.

Berry (1930, p. 66, pl. 48, figure 8) described a similar fossil fruit from the Puryear locality and assigned it to “ Ficus” fructus pedicellata . (mistakenly listed as “ Ficus” myrtifolia ovata Berry in the text). Berry’s specimen differs from the new species, Paleopanax puryearensis , in that “ Ficus” fructus pedicellata does not have D-shaped carpels, and the fruit is much smaller (10 mm long and 12 mm wide vs. 8 mm long and 10 mm wide).

Extant Araliaceae has about 50 genera mainly distributed in subtropical to tropical regions in both hemispheres and a few in temperate areas (Watson and Dallwitz, 1992 onwards; Xiang and Lowry, 2007; Xiang and Lowry, 2008). Manchester (1994) noted that the morphology of Paleopanax fruits is similar to the extant genus Pseudopanax . This is significant because Pseudopanax , with about 80 species of evergreen trees and shrubs, is native to New Zealand, Tasmania, New Caledonia, and Chile (Wen, 2001). Wen Jun (2019, personal communication) suggested that the Puryear fossil fruits are reminiscent of Metapanax , a genus presently distributed mostly in central and southwestern China and extending to northern Vietnam (Wen and Frodin, 2001).

Figures

FIGURE 31. Paleopanax puryearensis sp. nov.: 1, 2) UF15820-053151, 053151', part and counterpart of the holotype specimen showing laterally compressed, orbicular fruit with two persistent styles, two D-shaped carpels, and a pedicel. Scale bars equal 3 mm; 3, 4) Enlargements of Figure 31.1, 2, respectively, to show the curved styles and an epigynous disc (indicated by arrows). Scale bars equal 1 mm; 5, 6) UF15820-59481, 59481', part and counterpart of the paratype specimen showing D-shaped carpels. Scale bars equal 3 mm.