Taxonomic Study of the Fossil Species of the Genus Cryptantha (Boraginaceae)
1966; Southwestern Association of Naturalists; Volume: 11; Issue: 2 Linguagem: Inglês
10.2307/3669642
ISSN1943-6262
Autores Tópico(s)Plant and Fungal Species Descriptions
ResumoDistinguishing features of the fossil species of Cryptantha from the Pliocene Ogallala Formation are discussed. Comparisons are made to extant species where possible. Distributional ranges of the species are presented. Great quantities of fossil fruits, particularly of the plant family Boraginaceae, are represented in the Pliocene Ogallala Formation by nutlets of the extinct fossil genus Biorbia and the extant genus Cryptantha. The genus Biorbia has recently been studied (Segal, 1965); but except for a brief nomenclatural clarification (Segal, 1964) the fossil members of the genus Cryptantha have not been taxonomically treated since their original description (Elias, 1932). As Elias (1946) says, specific identification of Cryptantha fruits is possible. If other parts were involved they would be merely assigned to organ-genera (such as Borraginites) of problematic affinities. :I ~ ~ i ! I~~ ^~i Ai Si . . i i i -. -_ i iAAi i ,__,, ] i i ! ! -E . . .....-'.-..'-'-_, .L ._._ . !_o ! i 000i ' ..t ._._ j !i... l. _ ._ _ ,_._._ * I .R ! 'i i ' . . ....1-i . T !.._ . i j._._. I. -.. I_ . .-......... .... r r I (,.) I I i ' i I-.I ... ...... I O ! a ...... i .additionally in Yuma County, Colorado, immediately adjacent to Cheyenne County, Kansas. Plus sign, C. chaney; triangle, C. coroniformis; circle, C. uriculta. The number of times a symbol is repeated indicates the number of sites in a county. 205 ....% ~ ..-,;,,.,.,, 205... Fig. 2. Drawing of Cryptantha chaneyi. Each of the three fossil species discussed in this paper has unique features. No difficulties are encountered in identifying and distinguishing them. It is interesting to note that although extensive field work has been done in other areas by various workers (in addition to publications cited elsewhere: Elias, 1942; Frye and Leonard, 1957; Leonard, 1958), fossil species of Cryptantha are known only from Kansas, and one immediately adjacent site in Yuma County, Colorado (fig. 1). The genus Biorbia, on the other hand, is known to occur from South Dakota to Texas in abundant quantities. Key to the fossil species of Cryptantha A. N utlet m argin w inged B Margins without wings ........ C. coroniformis B. Nutlet width 1.4-1.6 m m C. auriculata Nutlet width 2.4-2.6 m m ......... C. chaneyi 1. Cryptantha chaneyi (Elias) Segal, Trans. Kans. Acad. Sci. 67: 203, 1964. Krynitzkia (Oreocarya) chaneyi Elias, Kans. Acad. Sci. 67: Bull. 20: 357-358, pl. 30, figs. 4a, 4b, 4c, 4d, 1932. Geol. Soc. Amer., Spec. Paper 41, 160, pl. 7, fig. 7, 1942. Type locality: south side of Goose Creek, Wallace County, Kansas.-Only nutlets known; hollow, greatly inflated, triangular-ovoid, acute at apex; triangular areola at base of scar of attachment on ventral surface; areola narrowing into
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