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Abstract BackgroundPonerine ants are almost exclusively predatory and comprise many of the largest known ant species. Within this clade, the genusNeoponerais among the most conspicuous Neotropical predators. We describe the first fossil member of this lineage: a worker preserved in Miocene-age Dominican amber from Hispaniola. ResultsNeoponera vejestoriasp. nov. demonstrates a clear case of local extinction—there are no known extantNeoponeraspecies in the Greater Antilles. The species is attributable to an extant and well-defined species group in the genus, which suggests the group is older than previously estimated. Through CT scan reconstruction and linear morphometrics, we reconstruct the morphospace of extant and fossil ants to evaluate the history and evolution of predatory taxa in this island system. ConclusionsThe fossil attests to a shift in insular ecological community structure since the Miocene. The largest predatory taxa have undergone extinction on the island, but their extant relatives persist throughout the Neotropics.Neoponera vejestoriasp. nov. is larger than all other predatory ant workers known from Hispaniola, extant or extinct. Our results empirically demonstrate the loss of a functional niche associated with body size, which is a trait long hypothesized to be related to extinction risk.
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This content will become publicly available on December 1, 2026
Trionychian turtles from the Early Miocene (Burdigalian) Moghra Formation, Egypt, including a new species of Carettochelyidae
Abstract Although trionychians have a rich fossil record, much of their fossil diversity is known from the Cretaceous and Paleogene, and little is known about their evolutionary history in the Neogene. We here describe cranial and shell material of trionychians from the Early Miocene Moghra Formation of Egypt that we attribute to a new carettochelyid taxon,Allaeochelys meylanisp. nov., and to theTrionyxlineage.Allaeochelys meylanisp. nov. fills a temporal gap between previously described taxa and exhibits a series of unique features, including greatly thickened cranial bones, a broad bony wall posterior to the orbit, a large fossa formed by the maxilla and premaxilla at the anterior third of the triturating surface, and a medial process on peripheral II.Allaeochelys meylanisp. nov. also documents the oldest occurrence ofCarettochelyidaeon the Afro-Arabian continent, while theTrionyxmaterial reported herein provides unambiguous evidence for the presence of this lineage on the Afro-Arabian continent no later than the Early Miocene.
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- Award ID(s):
- 2314898
- PAR ID:
- 10617883
- Publisher / Repository:
- Swiss Journal of Palaeontology
- Date Published:
- Journal Name:
- Swiss Journal of Palaeontology
- Volume:
- 144
- Issue:
- 1
- ISSN:
- 1664-2376
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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