Location
Culp Ballroom
Start Date
4-7-2022 9:00 AM
End Date
4-7-2022 12:00 PM
Poster Number
71
Faculty Sponsor’s Department
Geosciences
Name of Project's Faculty Sponsor
Steven Wallace
Competition Type
Competitive
Type
Poster Presentation
Project's Category
Biological Sciences
Abstract or Artist's Statement
Mustelids, members of the weasel family, are the most species rich and ecologically diverse family within the order Carnivora. However, fossil mustelids are poorly understood due to their rarity in the fossil record. Fossils of “Eurasian” badgers in particular, subfamily Melinae, only include three stem and two crown genera: Arctomeles, Arctonyx, Ferinestrix, Meles, and Melodon. Today, melines are restricted to the Old World, but fossils of stem taxa have also been discovered in North America. Here, I discuss the occurrence of the fossil meline Arctomeles dimolodontus currently known only from the Gray Fossil Site of East Tennessee, USA, and its phylogenetic position within stem Melinae. A total of 34 dental characters across 8 taxa were selected because some taxa, such as Arctomeles sotnikovae and Ferinestrix vorax, are known only from teeth (or cranial fragments). A search of all possible trees using PAUP (set for maximum parsimony) yielded a single most parsimonious tree. Topology of that tree suggests that Ferinestrix is nested within crown group Melinae, rather than the stem group, and is the sister to extant Arctonyx, the hog badger. Results also suggest that Arctomeles sotnikovae does not group within the monophyletic clade formed by A. dimolodontus and A. pliocaenicus, but instead nests A. sotnikovae as a closely related, but separate, lineage to Melodon. Based on these findings, we propose that the ancestral stock of crown Melinae is more closely related to Arctomeles than Meles as previous research has suggested. Furthermore, the dental morphology within stem Melinae is relatively conservative for a generalized diet, although exceptions exist in some derived forms, such as Arctonyx and Ferinestrix, which may explain why PAUP nested the two as sister taxa. Arctonyx is an exclusively Old-World lineage, so it is likely that the Arctonyx-Ferinestrix clade had an Old-World origin, after which Ferinestrix migrated into North America and Arctonyx remained in the Old World. This begs the question: why do some melines migrate into North America while other contemporary forms do not? All stem meline genera have occurrences from Eurasia, yet only Arctomeles and Ferinestrix are known to have migrated into North America. This is likely because of the environmental constraints on where these different genera can live, but much remains unknown about the ecology of fossil melines to know for certain. Further study of this disparity can lead to a greater understanding of how the earth’s climate has changed since the Neogene and how this change impacts flora and fauna.
Affinity of Arctomeles dimolodontus and other Old-World Badgers (Melinae: Mustelidae: Carnivora)
Culp Ballroom
Mustelids, members of the weasel family, are the most species rich and ecologically diverse family within the order Carnivora. However, fossil mustelids are poorly understood due to their rarity in the fossil record. Fossils of “Eurasian” badgers in particular, subfamily Melinae, only include three stem and two crown genera: Arctomeles, Arctonyx, Ferinestrix, Meles, and Melodon. Today, melines are restricted to the Old World, but fossils of stem taxa have also been discovered in North America. Here, I discuss the occurrence of the fossil meline Arctomeles dimolodontus currently known only from the Gray Fossil Site of East Tennessee, USA, and its phylogenetic position within stem Melinae. A total of 34 dental characters across 8 taxa were selected because some taxa, such as Arctomeles sotnikovae and Ferinestrix vorax, are known only from teeth (or cranial fragments). A search of all possible trees using PAUP (set for maximum parsimony) yielded a single most parsimonious tree. Topology of that tree suggests that Ferinestrix is nested within crown group Melinae, rather than the stem group, and is the sister to extant Arctonyx, the hog badger. Results also suggest that Arctomeles sotnikovae does not group within the monophyletic clade formed by A. dimolodontus and A. pliocaenicus, but instead nests A. sotnikovae as a closely related, but separate, lineage to Melodon. Based on these findings, we propose that the ancestral stock of crown Melinae is more closely related to Arctomeles than Meles as previous research has suggested. Furthermore, the dental morphology within stem Melinae is relatively conservative for a generalized diet, although exceptions exist in some derived forms, such as Arctonyx and Ferinestrix, which may explain why PAUP nested the two as sister taxa. Arctonyx is an exclusively Old-World lineage, so it is likely that the Arctonyx-Ferinestrix clade had an Old-World origin, after which Ferinestrix migrated into North America and Arctonyx remained in the Old World. This begs the question: why do some melines migrate into North America while other contemporary forms do not? All stem meline genera have occurrences from Eurasia, yet only Arctomeles and Ferinestrix are known to have migrated into North America. This is likely because of the environmental constraints on where these different genera can live, but much remains unknown about the ecology of fossil melines to know for certain. Further study of this disparity can lead to a greater understanding of how the earth’s climate has changed since the Neogene and how this change impacts flora and fauna.