186-7 An Investigation of Tropical Angiosperm Genome Sizes from the Albian-Cenomanian Une Formation of Colombia
Session: New Approaches to Old Fossil Collections (Posters)
Poster Booth No.: 71
Presenting Author:
Bryton SmithAuthors:
Smith, Bryton1, Zhang, Xiaoqing2, Shi, Gongle3, Jaramillo, Carlos4, Carvalho, Mónica5, Herrera, Fabiany6(1) University of Chicago, Chicago, USA; Field Museum, Chicago, USA, (2) Wesleyan University, Middletown, Connecticut, USA, (3) Nanjing Institute of Geology and Paleontology, Nanjing, China, (4) Smithsonian Tropical Research Institute, Panama City, Panama, (5) University of Michigan, Ann Arbor, USA, (6) Field Museum, Chicago, USA,
Abstract:
Ancestral character estimation suggests that flowering plants downsized their genomes in their early evolutionary history. In living angiosperms, genome size and guard cell length are generally strongly and positively correlated. Genome downsizing likely benefited early angiosperms physiologically and ecologically relative to gymnosperms and ferns, which ancestral character estimation suggests did not downsize their genomes during the Early Cretaceous. However, there are not yet sufficient Early Cretaceous guard cell length data to ground truth ancestral character estimates for Early Cretaceous angiosperm genome sizes and guard cell lengths, especially for tropical angiosperms. We are currently measuring guard cell lengths on abundant angiosperm cuticles from the Albian-Cenomanian Une Formation (Colombia) to infer paleogenome sizes. Our preliminary results show some variation in guard cell lengths among morphotypes, perhaps reflecting differences in ploidy level, repetitive DNA content, or both. Interestingly, our best-sampled morphotype, a eudicot with stomatal rings and reticulate venation, has the smallest guard cell lengths and therefore the smallest inferred genome size. Ultimately, we hope to contextualize our research in the framework of broader trends related to angiosperms’ ecological and evolutionary success.
Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025
doi: 10.1130/abs/2025AM-7830
© Copyright 2025 The Geological Society of America (GSA), all rights reserved.
An Investigation of Tropical Angiosperm Genome Sizes from the Albian-Cenomanian Une Formation of Colombia
Category
Discipline > Paleontology, Paleoecology/Taphonomy
Description
Session Format: Poster
Presentation Date: 10/21/2025
Presentation Room: HBGCC, Hall 1
Poster Booth No.: 71
Author Availability: 9:00–11:00 a.m.
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