Nanomechanical variability in the early evolution of vertebrate dentition

Abstract

Conodonts are an extinct group of primitive jawless vertebrates whose elements represent the earliest examples of a mineralized feeding apparatus in vertebrates. Their relative relationship within vertebrates remains unresolved. As teeth, conodont elements are not homologous with the dentition of vertebrates, but they exhibit similarities in mineralization, growth patterns, and function. They clearly represent an early evolutionary experiment in mineralized dentition and offer insight into analogous dentition in other groups. Unfortunately, analysis of functional performance has been limited to a handful of derived morphologies and material properties that may inform ecology and functional analysis are virtually unknown. Here we applied a nanoscale approach to evaluate material properties of conodont bioapatite by utilizing Atomic Force Microscopy (AFM) nanoindentation to determine Young’s modulus (E) along multiple elements representing different ontogenetic stages of development in the coniform-bearing apparatus of Dapsilodus obliquicostatus. We observed extreme and systematic variation in E along the length (oral to aboral) of each element that largely mirrors the spatial and ontogenetic variability in the crystalline structure of these specimens. Extreme spatial variability of E likely contributed to breakage of elements that were regularly repaired/regrown in conodonts but later vertebrate dentition strategies that lacked the ability to repair/regrow likely required the development of different material properties to avoid structural failure.

Leadership, Employee and Competency Development for Better Talent Management in the Face of the Dynamics of Environmental Changes

“…As the concept of Industry 4.0 is becoming more and more important, there is no doubt that digital competencies are crucial in various areas such as physics (Foadi and Varghese, 2022), education and higher education (Cattaneo, Antonietti, and Rauseo, 2022; Nunez-Canal, de Obesso, and Perez-Riviero, 2022; Saltos-Rivas, Novoa--Hernandez, and Rodriguez, 2022), healthcare (Heponiemi et al, 2022), business and banking (Norveel, Gonzalez, and Presthus, 2022), and public services (Morte--Nadal and Esteban-Navarro, 2022). The existence of the digital competence gap is confirmed by various research teams (Findeisen and Wild, 2022; Morgan, Sibson, and Jackson, 2022; Oberlander, Beinicke, and Bipp, 2022; as well as Shohel et al, 2022;Siggiq and Scherer, 2019). There is also a gap in learning digital competences (Svensson, Wilk, and Aman, 2022).…”

Anagenetic evolution and peramorphosis of a latest Devonian conodont from Holy Cross Mountain (Poland)

“…They hold a significant place in the study of vertebrate evolution, paleoecology, and biostratigraphy (e.g. Leonhard et al, 2021;Martínez-Pérez et al, 2016;Shohel et al, 2022;Sandberg and Ziegler, 1979). Characterized by their unique tooth-like structures, called conodont elements, they can be compared in terms of complexity to mammalian teeth (Donoghue and Purnell, 1999;Assemat et al, 2023).…”