Bonitasaura

*Bonitasaura salgadoi*

***Bonitasaura*** (La Bonita Lizard) is a small titanosaurian dinosaur measuring 9 meters (30 ft) long and could reach leaves about 3 meters (10 ft) above the ground. They lived 85 million years ago in the late Cretaceous Period. Unlike other sauropods, it has a relatively short neck. ‬The dorsal‭ (‬back‭) ‬vertebrae also had high and robust neural spines indicating points for strong muscle attachments.‭ ‬This could indicate that while the neck was short,‭ *‬Bonitasaura* were still high browsers that cropped mouthfuls of food from the tree canopy.

*Bonitasaura* is named after the La Bonita Quarry where the holotype remains were found in 2004.‭ ‬Because Bonita is a feminine Spanish word,‭ ‬the genus name has been named as‭ ‘‬saura‭’ ‬which is also feminine as opposed to‭ ‘‬saurus‭’ ‬which would be masculine‭ (‬both are Ancient Greek for lizard‭)‬.‭ ‬The species named *B.‭ ‬salgadoi* is in honor of the Argentine paleontologist Leonardo Salgado. The bones found include a partial vertebrae series and limb bones, as well as a lower jaw with teeth. This was significant since most Titanosaurs' skulls are separated from their bodies during decomposition. The jaw has a sharp ridge directly behind the teeth, which were covered in keratin. A similar structure was probably on the upper jaw, and most likely chopped the vegetation that the teeth pulled in.

## Description

*Bonitasaura* measured 9 meters (30 feet) in length, and had a skull similar to another group of sauropods, the diplodocids. The lower jaw had a distinctive, sharp ridge immediately behind a reduced set of teeth. This ridge supported in life a sharp, beak-like keratin sheath that probably paired with a similar structure in the upper jaw. The keratin sheath worked much like a guillotine to crop vegetation raked into the mouth by the peg-like front teeth. This animal also had a rather short neck and robust projections of the back vertebrae for muscle attachment, indicating that the neck was use in vigorous exertions, probably during feeding.

*B. salgadoi* is further evidence that, after a purported extinction of diplodocid sauropods, some lines of titanosaurian evolution converged with them, exhibiting low long skulls without the characteristic nasal arches of other macronarians (such as *Brachiosaurus* or *Argentinosaurus*) and lower jaws that were squared off and contained comb-like teeth, reversed limb proportions (the front limbs shorter than the hind limbs, unlike the condition in most other macronarians) and rudimentary whiplash tails. This find also sheds light on some problematic aspects of the related dinosaur *Antarctosaurus*, sometimes viewed as a chimera made up of a titanosaurian skull and body and a diplodocid jaw.

## Classification

*Bonitasaura* was first considered a nemegtosaurid in the description paper, but cladistic analysis placed it as a eutitanosaur.

## Appearance in other media

### *Jurassic Park*

* *Bonitasaura* appears in *Jurassic World: The Game* as a dinosaur that can be obtained for the player's park.

## References

* Sebastián Apesteguía. (September 2004). *Bonitasaura salgadoi* gen. et sp. nov.: a beaked sauropod from the Late Cretaceous of Patagonia. *Naturwissenschaften*. 91:493–497