Abstract Detail

Paleobotany

Correa, Julian [1], Manchester, Steven [2], Hermsen, Elizabeth J. [3], Allen, Sarah E. [4].

Tracing the fossil Land­eenia aralioides to its family – additional characters and a morphological comparison to modern Sapindales.

Landeenia aralioides (MacGinitie) Manch. & Hermsen is a fossil genus and species based on flowers with in situ pollen, fruits, and dispersed seeds from the Eocene of Wyoming. Landeenia Manch. & Hermsen appeared during the Paleocene-Eocene thermal maximum (PETM). The taxon was common in early Eocene floras—it is known from Blue Rim (southwestern Wyoming), Tipperary, Kisinger Lakes (both northwestern Wyoming), and PETM sites in the Bighorn Basin (northwestern Wyoming)—but disappeared from the record by the middle Eocene (Bridgerian). The taxon has been tentatively placed in Sapindales, a diverse order of eudicot angiosperms that includes nine extant families. This placement is suggested by its five-merous calyx, nectary disk, superior ovary of multiple fused carpels, single style, capsulate fruit, and tricolpate (to tricolporate) pollen; the numbers of carpels (~18 – relatively high in Sapindales) and stamens (~4–10 stamens) in Landeenia flowers suggest an affinity to the Rutaceae or Meliaceae. Odd-pinnate compound leaves known as “Cedrela” schimperi (Lesquereux) MacGinitie co-occur with Landeenia at all localities and are here hypothesized to represent the same plant; the leaflets have brochidodromous venation and entire margins, features consistent with the Sapindales and other families. Fossil wood found in association with Landeenia at Blue Rim (“Blue Rim Xylotype 3” of S. Allen, Florida Museum of Natural History specimen UF 19225-57353) may possibly correspond to the Landeenia plant, although inclusion of wood anatomical characters weakens support for assignment of the reconstructed plant to Sapindales. A few other families and orders could accommodate a portion of the suite of characters found in Landeenia, but taxa in those families usually have various traits that are contradictory. In an attempt to better understand the position of Landeenia within Sapindales, we are developing a morphological character matrix for comparative analyses of extant and fossil Sapindales.

1 - University of Florida, Florida Museum of Natural History, Dickinson Hall;1659 Museum Rd, Gainesville , FL, 32611-7800 , USA
2 - Florida Museum of Natural History, 1659 Museum Rd, Gainesville, FL 32611, United States, Gainesville, FL, 32611, United States
3 - Paleontological Research Institution, 1259 Trumansburg Road, Ithaca, NY, 14850, United States
4 - Penn State Altoona, Biology, 206 Hawthorn, 3000 Ivyside Park, Altoona, PA, 16601, USA

Keywords:
Sapindales
Eocene
Taxonomy
wood
Matrix
fossil fruit
pollen.

Presentation Type: Oral Paper
Session: PL1, Paleobotany: Cookson Student Presentations - Session I
Location: /
Date: Monday, July 19th, 2021
Time: 11:15 AM(EDT)
Number: PL1006
Abstract ID:1041
Candidate for Awards:Isabel Cookson Award,Maynard F. Moseley Award