Fossil Leguminosae are among the most abundant and diverse elements in the flora of the Eocene Claiborne Formation of southeastern North America. The three legume subfamilies, Caesalpinioideae, Mimosoideae, Papilionoideae, are represented by numerous leaflet and fruit species as well as by several species of flowers. A particular type of leaf, fruit and/or inflorescence co-occur at four of the twelve localities that have been examined and have been shown to have affinities with the tribe Mimoseae of the Mimosoideae. The fossil leaves (Duckeophyllum eocenicum gen. et sp. nov.) are bipinnate with prominent pulvinae on the petiole and rachises. The leaves supported at least four pairs of pinnae, each bearing five or more pairs of opposite to alternate inequilateral coriaceous leaflets. These fossils are similar to the extent monotypic genus Dinizia from Amazonian Brazil. The co-occurring fossil inflorescence, Eomimosoidea plumosa Crepet and Dilcher, has also been compared with Dinizia. Specimens of fossil pods (Eliasofructus catahoulensis and E. claibornensis gen. et spp. nov.) are comparable to the fruits of Dinizia in some respects and differ from them in others. Dinizia is one of the most generalized and isolated genera of the Mimoseae and is thought to have diverged very early in the evolution of the Mimosoideae. These fossils provide evidence for the occurrence of the Mimosoideae in southeastern North America during the Eocene and are of evolutionary significance because of the hypothesized basal position of Dinizia in the Mimoseae. Leaflets similar in general form to the leaflets examined in this study have often been assigned to Mimosites Bowerbank, a genus established for legume fruits referable to the Mimosoideae at large with unknown modern relationships. After reviewing the history of the use of the name Mimosites, we establish the new generic name Parvileguminophyllum for small inequilateral legume leaflets and make new combinations for the Mimosites species described by Berry (1914, 1916, 1924, 1930) for small legume leaflets.
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