Morphology and Size
The fossil remains of Albertonectes are notable for their exceptional cervical vertebrae count. With 76 individual neck vertebrae, Albertonectes holds the record for the most neck vertebrae among known vertebrates. The overall body plan adheres to the typical plesiosaur morphology—featuring a compact, robust torso; relatively short tail; and four flipper-like limbs adapted for efficient aquatic locomotion.
The neck of Albertonectes measured approximately 7 meters (23 feet), which accounts for over half of the total estimated body length of 11.6 meters (38 feet). This elongated, rigid neck likely played a crucial role in its feeding strategy, although fossil evidence suggests that the neck in the holotype specimen was damaged post-mortem, complicating efforts to reconstruct its range of motion. The adult mass has been estimated at approximately 4.8 metric tons.
Distinguishing anatomical features of Albertonectes include a pronounced anterior extension of the pubis adjacent to the acetabulum and a broader-than-usual scapular arch. Additionally, the caudal region displays seven fused vertebrae, and the specimen suggests possible fusion of neural spines in the adult form.
Dietary Habits
As a presumed carnivore, Albertonectes likely fed on small aquatic prey. Its dentition, characterized by slender yet robust teeth with deep roots, suggests a specialization for capturing soft-bodied and slippery organisms such as small fish and cephalopods. The dentary and maxillary teeth likely interlocked when the jaws closed, enhancing prey retention. The structure of its jaws, inferred from related taxa, implies limited capability for dismembering large animals, favoring instead a diet of smaller, more manageable prey.
Interestingly, gastroliths—stones found in the abdominal region—have been recovered from the holotype. Their presence is still debated but may have served either as a ballast to aid in buoyancy control or as a digestive aid, similar to that seen in some modern and extinct vertebrates.
Paleoenvironment and Distribution
Albertonectes existed during the Campanian stage of the Late Cretaceous and inhabited the Western Interior Seaway—a vast, shallow inland sea that once split North America. The only known specimen was recovered from the Bearpaw Formation, located south of Lethbridge, Alberta, Canada, suggesting it occupied pelagic marine environments rather than being restricted to coastal regions.
Discovery and Taxonomic History
The holotype specimen of Albertonectes vanderveldei was serendipitously unearthed in 2007 by Korite International, a company primarily involved in the extraction of ammonite fossils for ornamental purposes. Excavation was facilitated by heavy machinery typically used for mining ammonite-bearing rock, which inadvertently exposed the fossil.
The Royal Tyrrell Museum subsequently led a professional excavation of the site, recovering most of the skeleton apart from the skull. The specimen, dated to approximately 73.5 million years ago, was found within the Muddy Unit 1 of the St. Mary River section. The species was formally described in 2012 by paleontologists Tai Kubo, Mark Mitchell, and Donald Henderson. The species epithet "vanderveldei" honors René Vandervelde, founder of Korite International, while the genus name reflects the geographic origin in Alberta.
Predation and Threats
While direct evidence of predation is scarce, fossil analysis revealed tooth marks consistent with scavenging by sharks from the genus Squalicorax. The positioning and nature of these marks indicate post-mortem feeding activity. Larger marine predators, such as mosasaurs, may have also posed a threat to Albertonectes, though definitive evidence remains elusive. Given their considerable size and likely slow swimming speed, adult Albertonectes individuals may have been vulnerable to apex predators.
Extinction
Albertonectes became extinct by the end of the Late Cretaceous, preceding the Cretaceous–Paleogene (K–Pg) extinction event approximately 66 million years ago. This mass extinction, likely triggered by a bolide impact near the present-day Yucatán Peninsula, led to drastic environmental changes including global darkness, acid rain, and ocean acidification, which decimated marine and terrestrial ecosystems. All surviving members of Plesiosauria, including Albertonectes, vanished during this period.
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