Longest-necked animal ever (number of vertebrae)

Based on the number of cervical (neck) vertebrae, the animal with the longest neck (living or extinct) is the plesiosaur Albertonectes vanderveldei, a marine reptile that was unearthed in the Upper Cretaceous Bearpaw Formation in southern Alberta, Canada. This record is based on the holotype specimen TMP 2007.011.0001, a nearly complete skeleton, missing only the skull and portion of the fore and hind limb. The specimen is 11.2 m (36 ft 2 in) in postcranial length - 7 m (23 ft) of which is neck and comprised of 76 cervical vertebrae. It is also the longest neck in terms of total length of any plesiosaur. The specimen is housed at the Royal Tyrrell Museum in Drumheller, Alberta, Canada.

The specimen was discovered incidentally during mining (Korite International Ltd) for gem-quality ammonite shell ("Ammolite") in May 2007, and collected by crews from the Royal Tyrrell Museum in the following weeks. Details of the specimen were first described in the Journal of Vertebrate Paleontology in a paper published on 3 May 2012.

Prior to A. vanderveldei, the animals with the most neck vertebrae were another type of plesiosaur known as elasmosaurs, a genus of marine reptiles that lived in the Late Cretaceous. One in particular, Elasmosaurus platysaurus, was noted for its extremely high cervical vertebrae count - a figure long held to be 71 that was recently revised to 72. Some palaeontologists have questioned whether the count of 76 for A. vanderveldei may, in fact, be 75 if the bottommost vertebra is considered part of the pectoral, rather than cervical, series, but in either case this species still maintains the record.

In terms of total length, there may have been longer necks among terrestrial prehistoric reptiles. For instance, the sauropod Sauroposeidon, which lived c. 110 million years ago in the mid-Cretaceous, may have had a neck that stretched to 11-12 m (36-39 ft), or even longer by some accounts. Despite the great length of sauropod necks, the maximum number of cervical vertebrae found in a species to date is 19. The neckbones were just proportionately huge in keeping with these dinosaurs' overall giant dimensions; one individual Sauroposeidon vertebra measured 1.2 m (4 ft) long.