Structural pattern in the tusks of the Miocene mammutid Zygolophodon turicensis and its utility in the taxonomy of elephantimorph proboscideans. (2nd December 2021)

• Record Type: Journal Article
• Authors: Březina, Jakub; Ivanov, Martin; Madzia, Daniel
• Is Part Of: Historical biology. Volume 33:Number 12(2021)
• Page Start: 3191
• Page End: 3201
• Publication Date: 2021-12-02
• Subjects: Schreger pattern -- tusk -- Zygolophodon -- Mammutidae -- Proboscidea -- Miocene; Paleobiology -- Periodicals; Biology -- Periodicals; Evolution -- Periodicals; Paleontology -- Periodicals; Biology -- Periodicals; Paleontology -- Periodicals; Evolution -- Periodicals; 560.5
• DOI: 10.1080/08912963.2020.1853720
• Languages: English
• ISSNs: 0891-2963

Abstract

ABSTRACT: The cross sections of tusks of all elephantimorph proboscideans show well-developed intersecting lines that form a conspicuous net-like structure termed the Schreger pattern. This trait is usually used to discriminate the tusks of recent elephants from those of mammoths. In Neogene elephantimorphs, however, the pattern remains largely unstudied and its utility unexplored. This study provides the first detailed assessment of the Schreger pattern in a Neogene elephantimorph. We have obtained thin sections from the basal half of the upper tusks of Zygolophodon turicensis, a mammutid from the middle Miocene of the Czech Republic, provide the full description of Schreger pattern and assess its utility in elephantimorph taxonomy. The arrangement of Schreger lines more closely resembles that of Anancus arvernensis and mammoths rather than that of Mammut americanum, a mammutid closely related to Z. turicensis . We further found that the visibility of the Schreger pattern can be affected by mineralisation as well as by the natural formation of dentin. Our results indicate that the appearance of the inner structure of elephantimorph tusks is not associated with their shape and is probably not reflective of phylogenetic affinities. Still, the appearance of the Schreger pattern remains useful for species identification.