Research Institute of Electrical Communication, Tohoku University, Sendai, 987-0833, Japan.
Graduate School of Engineering, Tohoku University, Sendai, 987-8579, Japan.
Sci Rep. 2024 Oct 28;14(1):25333. doi: 10.1038/s41598-024-55805-z.
A locomotor system that can function across different environmental conditions and produce a range of performances is one of the most critical abilities needed for extant and extinct animals in order to survive and maximise their competitive fitness. Recent engineering-inspired paleontological studies have reconstructed feasible locomotor patterns in extinct animals. However, it is still challenging to describe how extinct animals successfully adjust their locomotor patterns to new situations (e.g., changes in locomotor speed and morphology). In this study, we develop a novel reconstruction method based on a bio-inspired control system. We focus on plesiosaurs, an extinct aquatic reptile group which has two pairs of flipper-shaped limbs, and demonstrate that a highly optimised, flexible locomotor pattern for all four flippers can be reconstructed based on a decentralized control scheme formulated from extant animals' locomotion. The results of our robotic experiments show that a simple, local sensory feedback mechanism allows the plesiosaur-like robot to exploit the fluid flow between the flippers and generate efficient swimming patterns in response to changes in locomotor conditions. Our new method provides further evidence how decentralized control systems can produce a pathway between extinct and extant animals in order to understand the how extinct animals moved and how these movement patterns may have evolved.
一个能够在不同环境条件下运作并产生多种表现的运动系统，是现存和已灭绝动物为了生存和最大限度地提高其竞争适应性所需的最关键能力之一。最近受工程启发的古生物学研究已经重建了已灭绝动物可行的运动模式。然而，描述已灭绝动物如何成功地调整其运动模式以适应新情况（例如，运动速度和形态的变化）仍然具有挑战性。在本研究中，我们开发了一种基于生物启发控制系统的新重建方法。我们专注于已灭绝的水生爬行动物——蛇颈龙，它们有两对鳍状肢，并证明基于从现存动物的运动中制定的分散控制方案，可以为所有四个鳍重建高度优化、灵活的运动模式。我们的机器人实验结果表明，一个简单的、局部的感官反馈机制允许类蛇颈龙机器人利用鳍之间的流体流动，并根据运动条件的变化产生高效的游泳模式。我们的新方法进一步证明了分散控制系统如何在已灭绝和现存动物之间产生一种途径，以了解已灭绝动物的运动方式以及这些运动模式是如何进化的。
