Geological Society of America

T12 Exploring the Mechanisms of Morphologic Change I

Sunday, 9 October 2022
8:00 AM - 12:00 PM
Mile High Ballroom 4A

ORIGINS OF THE ECHINOZOAN BODY PLAN

Paper number: T12-11
Program: Technical Sessions
Time: 10:20 AM – 10:35 AM

Authors

Jeffrey Thompson Presenting Author
The Natural History Museum, London
Jeffrey Thompson Presenting Author
University of Southampton, Southampton
Imran Rahman
The Natural History Museum, London
Mike Reich
3Landesmuseen Braunschweig | Staatliches Naturhistorisches Museum, Braunschweig
Timothy A.M. Ewin
The Natural History Museum, London
Nicolas Mongiardino koch
Yale University, New Haven, CT
Zoë X. Schultz
University College London, London
Paola Oliveri
University College London, London
Ferdinand Marlétaz
University College London, London
Samuel Zamora
Zaragoza

Abstract

Echinozoans, the group of animals including echinoids (sea urchins) and holothurians (sea cucumbers) is a diverse clade occupying a range of ecologies and habitats in today’s oceans. Modern echinozoans occupy a disparate range of body plans, from the soft-bodied vermiform holothurians, to the multi-plated globular echinoids. Echinozoans are first known from the Ordovician period, and despite their well-characterized body plans in modern ecosystems, little is known of the morphological characterization of their earliest representatives. To better understand the this, we used a multilevel approach that combines paleontological, genomic, and developmental data. We first carried out micro-CT scanning of various basal taxa, which clarifies the morphological transitions characterizing the early evolution of their body plans. We then constructed a character matrix encompassing numerous Paleozoic echinozoans, along with other echinoderm outgroups, to understand the inter-relationships of echinozoan classes, and their relationships to other eleutherozoans (including asteroids, ophiuroids, and edrioasteroids). We then analyzed changes in disparity leading from their earliest members, up to those of the crown group. Finally, to understand the genomic underpinning of the morphological changes that characterize echinozoan bodyplans, we carried out analyses of gene content from genomes and transcriptomes of extant species, to understand sources of genomic novelty, and analyzed the expression of key genes involved in the development of the their body plans. This sheds new light on the origin of the echinozoan body plan from paleontological, genomic, and developmental perspectives.

Geological Society of America Abstracts with Programs. Vol. 54, No. 6

doi: 10.1130/abs/2022AM-380031

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