Caesalpinia claibornensis Herendeen and Dilcher, 1991

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 : 8-9

Caesalpinia claibornensis Herendeen and Dilcher, 1991

Figure 10

1991 Caesalpinia claibornensis Herendeen and Dilcher , p. 3, figs. 1–12.

2013 Caesalpinia claibornensis Herendeen and Dilcher ; Wang, Blanchard, and Dilcher, p. 15, figs. 13.4–5.

Description. “The fossil fruits are 5.1–8.1 cm long (x = 6.9 cm), 1.2–2.1 cm wide (x = 1.7 cm, excluding the wing) and have a continuous vascularized wing along the placental suture that is usually wider at the fruit center than at the ends. The fruits are thin and membranous. The fruit base is acute to obtuse, the apex is blunt and rounded or occasionally mucronate with a persistent style base (ca. 1 mm long). The fruits are short stipitate (ca. 2 mm) and contain three to seven ovules. The fruit valve venation consists of numerous, closely spaced primary veins that arise from the placental and nonplacental sutures at 90° angles. These veins divide and anastomose to form a fine reticulum. The wing venation consists of a poorly organized storied looping pattern in which veins arise from the placental suture, divide several times, and return toward the suture. The valve venation is often better preserved than is the wing venation.” (Herendeen and Dilcher, 1991, p. 3)

Number of specimens examined. 2. UF15820- 005854, 005855.

Remarks. These are the two paratype specimens described and illustrated by Herendeen and Dilcher (1991, p. 3, figures 11, 12). We re-illustrate them here to demonstrate the occurrence of this species at the Puryear locality, Tennessee.

Three species were recognized within Caesalpinia L. subgenus Mezoneuron (Desf.) Vidal ex Herendeen and Zarucchi by Herendeen and Dilcher (1991). Eighteen specimens of Caesalpinia claibornensis are recognized from the Eocene Claiborne Group, two specimens of Caesalpinia flumen-viridensis from the Eocene Green River Formation in southwestern Wyoming, and 12 specimens of Caesalpinia spokanensis from the Miocene Latah Formation near Spokane, Washington and Coeur d’Alene, Idaho, and the Clarkia, Oviatt Creek, and Whitebird floras in Idaho. These specimens, which are the only reliable evidence of C. subg. Mezoneruron in the fossil record, show that this group had a broad geographic and temporal range in North America before its extinction, perhaps in the late Miocene (Herendeen and Dilcher, 1991).

Figures

FIGURE 10. Caesalpinia claibornensis Herendeen and Dilcher, 1991: 1) UF15820-005854, incomplete fruit showing both valve and wing venation; 2) UF15820-005855, incomplete fruit showing both valve and wing venation. All scale bars equal 5 mm.