T66 Phylogenetic and Computational Approaches in Paleobiology II

Sunday, 22 September 2024
1:30 PM - 5:30 PM
204A

BACULITID PHYLOGENETIC RECONSTRUCTION FROM A BAYESIAN PERSPECTIVE

Paper number: T66-2
Program: Technical Sessions
Time: 1:45 PM – 2:00 PM

Authors

Abstract

Baculitidae, a family of heteromorph ammonoid cephalopods, are well known for their use in biostratigraphy, especially in the Late Cretaceous North American Western Interior Seaway (WIS). However, the understanding of evolutionary relationships between species of baculitids not only in the WIS but also in other North American localities has been limited thus far. A Bayesian phylogenetic analysis was performed on North American baculitids using the fossilized birth-death model, a relatively new method for reconstructing morphology-based phylogenies from a Bayesian approach. A total of 23 baculitid ornamentation, shell shape, and suture characters were coded in a character matrix for 43 operational taxonomic units. Estimated ranges for first appearances were drawn from occurrences in the Paleobiology Database. The evolutionary relationships of Late Cretaceous baculitid species from the North American Eastern Pacific Coast, Western Interior Seaway, Gulf Coastal Plain, and Atlantic Coastal Plain were modeled to produce a time calibrated Maximum Compatibility Tree. Speciation, extinction, sampling, diversification, and turnover rates were also obtained over 10 intervals through the Cretaceous. Sciponoceras, one of the earliest baculitid genera, forms the basal stem of the family. One of the most well supported clades in this phylogenetic tree suggests that the turnover event at the Cenomanian-Turonian boundary, associated with Ocean Anoxic Event 2, gave rise to the clade that contains most of North America’s Baculites species. The tree also suggests that several Baculites species anagenetically evolved into Trachybaculites and Eubaculites species, indicating the need for taxonomic revisions within this important ammonoid family.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-404596

© Copyright 2024 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.