Named By: Paul Upchurch, Philip D. Mannion & Michael P. Taylor - 2015.
Synonyms: Pelorosaurus becklesii.
Classification: Chordata, Reptilia, Dinosauria, Sauropodomorpha, Sauropoda, Macronaria?
Species: H. becklesii (type).
Size: Uncertain due to lack of fossil remains, however, humerus is recorded as being 59.9 centimetres long, ulna, 42.1 centimetres long and radius 40.4 centimetres long. Using more complete genera such as Camarasaurus results in a reconstructed length of about 6.5 meters long, though this is just a best guess.
Known locations: England - Hastings Beds Group.
Time period: Late Berriasian of the Cretaceous.
Fossil representation: Fore limb bones including humerus (upper fore leg bone) and an ulna and radius (lower leg bones). A skin impression is also known.
holotype bones of Haestasaurus were originally
found in 1852 by a
man named Samuel Husband Beckles who found them exposed by a low tide
on a coast not far from Hastings. These remains were studied by
Gideon Mantell (best remembered for naming Iguanodon)
considered them to represent a second species of the sauropod
becklesii (in honour of Samuel Beckles who found the
bones consisted of a partial fore limb and remained in the private
collection of Samuel Beckles until 1891 when they were acquired by
the British Museum of Natural History.
However, speculation about the correct identity of the fossils already started before they were acquired by the British Museum of Natural History. Casts of the bones had been made before 1891, and these were being studied as early as 1888. Initially, and possibly unaware that the fossils had been used as a basis for a second species of Pelorosaurus, Richard Lydekker mistakenly attributed to the fossil location of the bones as the Isle of Wight, which is quite some way from Hastings. For the record, we currently do not know the precise fossil location of the holotype bones other than somewhere on the coastline of Hastings.
Another noted American palaeontologist named Othniel Charles Marsh considered the bones to represent a species of Morosaurus in 1889. Lydekker disagreed with this and instead chose to list it as a species of Cetiosaurus (in addition to this Morosaurus is now considered to be a synonym to Camarasaurus). Much later in 1932, Friedrich von Huene was of the opinion that Pelorosaurus becklesii should be a distinct genus but did not create a name. He also noted a similarity to either Camarasaurus or Brachiosaurus, again indicating a similarity with macronarian sauropods. Later again in 1990, John Stanton noted that fossils of Pelorosaurus becklesii were not co-generic with the Pelorosaurus type species P. conybeari.
In 2015 Pelorosaurus becklesii was finally given its own genus in a study by Paul Upchurch, Philip Mannion and Michael Taylor. The new name was Haestasaurus, meaning ‘Haesta lizard’ and was named after an anglo-saxon war chief called Haesta, whose name would also go on to derive the modern name of Hastings. Because only some fore limb bones exist it has been difficult to definitively ascertain what kind of sauropod Haestasaurus was. Earlier interpretations of the holotype bones suggest that Haestasaurus was a macronarian sauropod similar to Camarasaurus, and indeed this may still be valid. Although macronarian sauropods were most common in the Late Jurassic, some are known in the early Cretaceous, with some genera such as Brontomerus being known to have existed even later that Haestasaurus. Another idea is that Haestasaurus may be a titanosauriform or even a primitive titanosaur, which have their evolutionary roots within the macronarian sauropods. The bones of Haestasaurus do show a degree of thickening to them which is a feature seen in titanosaurs, however they are not thickened to a degree that would make them exclusively titanosaurian, and may even represent a transitional stage. Ultimately however more fossil discoveries are needed to reveal more information about Haestasaurus.
- The anatomy and phylogenetic relationships of ‘Pelorosaurus’ becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England. - PLoS ONE 10(6):e0125819:1-51. - P. Upchurch, P. D. Mannion & M. P. Taylor - 2015.