Alexandronectes
| Alexandronectes Temporal range: Maastrichtian ~
| |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | †Sauropterygia |
| Order: | †Plesiosauria |
| Family: | †Elasmosauridae |
| Genus: | †Alexandronectes Otero et al., 2016 |
| Species: | †A. zealandiensis
|
| Binomial name | |
| †Alexandronectes zealandiensis Otero et al., 2016
| |
Alexandronectes is a genus of elasmosaurid plesiosaur, a type of long-necked marine reptile, that lived in the oceans of Late Cretaceous New Zealand. It contains one species, A. zealandiensis.[1] Fossils of Alexandronectes were found in the Conway Formation of Canterbury,[2] which can be dated to the Early Maastrichtian stage of the Cretaceous. Fossils of it were found around 1872 near the Waipara River, north of Christchurch, New Zealand. [3]
Description
Alexandronectes belongs to the elasmosaurid subfamily Aristonectinae based on the pterygoid structure and an A-shaped squamosal arch. However, it differs from other aristonectines in its smaller skull, different paroccipital processes, and different mandibular glenoid.[1] A 2021 study used CT scans to create digital reconstructions of the holotype, and detected the stapes in the inner ear, marking the first time this bone has been found in an aristonectine. The study also found a recess in the floccular lobe of the cerebellum, which may have functioned to stabilize both the head and the retinal image of Alexandronectes. This is the first occurrence of this feature in an elasmosaurid. [3]
References
- ^ a b Otero, Rodrigo A.; O'Gorman, José P.; Hiller, Norton; O'Keefe, F. Robin; Fordyce, R. Ewan (2016). "Alexandronectes zealandiensis gen. et sp. nov., a new aristonectine plesiosaur from the lower Maastrichtian of New Zealand". Journal of Vertebrate Paleontology. 36 (2): e1054494. doi:10.1080/02724634.2015.1054494. S2CID 87048127.
- ^ Waipara River, M34/f1073 at Fossilworks.org
- ^ a b O'Gorman, Jose P.; Otero, Rodrigo A.; Hiller, Norton; O'Keefe, Robin F.; Scofield, R. Paul; Fordyce, Ewan (2021-03-04). "CT-scan description of Alexandronectes zealandiensis (Elasmosauridae, Aristonectinae), with comments on the elasmosaurid internal cranial features". Journal of Vertebrate Paleontology. 41 (2). doi:10.1080/02724634.2021.1923310. ISSN 0272-4634. S2CID 237518012.
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