The Simulation of the Walking Gait of the Extinct Trigonotarbid Arachnid

Abstract

Trigonotarbids are amongst the earliest known terrestrial predators. They lacked obvious predatory adaptations seen in many modern arachnids. Hence, the ability of trigonotarbids to run prey down was important in their success as a predator. Studying their locomotion could be important for understanding early terrestrial ecosystems, and the evolution of arachnid gaits. Previous studies have created 3D computer models of Palaeocharinus specimens, reconstructed from Rhynie Chert fossils including limb articulation. Here we use a computational approach to simulate biologically try to produce stable gaits seen in modern day arachnids and then assess their efficiency. In order to test these gaits a morphologically accurate 3D computer model has been created from photographs of thin section material. Advance micro CT imaging techniques have also been used to make inferences about musculature, that evades adequate preservation, from modern analogues. The simulations have produced a stable alternating tetrapod gait with duty factors consistent with the expected values for an alternating tetrapod gait for the first three pairs of legs. However, the duty factors for the fourth pair of legs are far more than expected as they drag on the ground to provide support for the opisthosoma. Further simulations need to be carried out in order to produce more accurate gaits and test their relative efficiency.

Date of Award	31 Dec 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Russell Garwood (Supervisor)