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DeutschMarambionectes
| Marambionectes Temporal range: Late Cretaceous | |
|---|---|
 | |
| Speculative life restoration | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | †Sauropterygia |
| Order: | †Plesiosauria |
| Superfamily: | †Plesiosauroidea |
| Family: | †Elasmosauridae |
| Clade: | †Weddellonectia |
| Genus: | †Marambionectes O'Gorman et al., 2024 |
| Species: | †M. molinai |
| Binomial name | |
| †Marambionectes molinai O'Gorman et al., 2024 | |
Marambionectes (meaning "Marambio Island swimmer") is an extinct genus of weddellonectian elasmosaurid plesiosaur from the Late Cretaceous López de Bertodano Formation of Antarctica. The genus contains a single species, M. molinai, known from a partial skeleton.
Discovery and naming
[edit]The Marambionectes holotype specimen, IAA-Pv 752, was discovered in 2018 in sediments of the López de Bertodano Formation (unit 9) near on Marambio (Seymour) Island of James Ross Archipelago, Antarctica. The specimen is partially articulated and incomplete, consisting of the basioccipital, mandible, some teeth, cervical, pectoral, dorsal, and caudal vertebrae, ribs, an ilium, the right humerus and ulna, and a femur. The specimen belongs to an adult animal.[1]
In 2024, O'Gorman and colleagues described Marambionectes molinai as a new genus and species of elasmosaurid plesiosaur based on these fossil remains. The generic name, Marambionectes, combines a reference to Marambio Island, where the fossil material was found, with the Greek word "nectes", meaning "swimmer". The specific name, molinai, honors the Argentinian fossil preparator Omar J. Molina and his Antarctic field work.[1]
Classification
[edit]In their phylogenetic analyses, O'Gorman et al. (2024) recovered Marambionectes as a derived member of the elasmosaurid clade Weddellonectia, as the sister taxon to the Aristonectinae.[1] Nearly identical results were recovered by O'Keefe et al. (2025) in an updated version of this phylogenetic matrix, with Marambionectes as the aristonectine outgroup. These results are shown in the cladogram below. The ⊞ button can be clicked to expand the node.[2]
| Weddellonectia |
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References
[edit]- ^ a b c O'Gorman, Jose P.; Canale, Juan I.; Bona, Paula; Tineo, David E.; Reguero, Marcelo; Cárdenas, Magalí (2024-12-31). "A new elasmosaurid (Plesiosauria: Sauropterygia) from the López de Bertodano Formation: new data on the evolution of the aristonectine morphology". Journal of Systematic Palaeontology. 22 (1). Bibcode:2024JSPal..2212302O. doi:10.1080/14772019.2024.2312302. ISSN 1477-2019.
- ^ O'Keefe, F. Robin; Armour Smith, Elliott; Clark, Robert O.; Otero, Rodrigo A.; Perella, Anna; Trask, Patrick (2025-05-22). "A name for the Provincial Fossil of British Columbia: a strange new elasmosaur taxon from the Santonian of Vancouver Island". Journal of Systematic Palaeontology. 23 (1). doi:10.1080/14772019.2025.2489938. ISSN 1477-2019.
- ^ O’Gorman, Jose P. (2020-03-13). "Elasmosaurid phylogeny and paleobiogeography, with a reappraisal of Aphrosaurus furlongi from the Maastrichtian of the Moreno Formation". Journal of Vertebrate Paleontology. 39 (5): e1692025. Bibcode:2019JVPal..39E2025O. doi:10.1080/02724634.2019.1692025. ISSN 0272-4634. S2CID 215756238.
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