Iberospinus

Before formal naming or identification, this organism was known as the following on this wiki:
**Praia das Aguncheiras spinosaur**

## Statistics

### Diet

Carnivorous

*Iberospinus* is an extinct genus of Spinosaurid theropod dinosaurs that lived in Portugal during the Early Cretaceous.

## History

The holotype of *Iberospinus* is known from between Rochadouro and Areia do Mastro, above a low cliff that overhangs the foreshore and beach at Boca do Chapim during expeditions from 2004-2008 and discovered by Carlos Natário. The holotype is ML1190 (deposited at the Museum of Lourinhã), which was referred to previously as *Baryonyx* and spinosaurid indet., where it was named as distinct in 2022 by Octávio Mateus and Darío Estraviz-López. Undescribed elements were found in an expedition in June 2020, including a partial left dentary with at least 4 teeth, an isolate complete tooth, 2 fragmentary isolate teeth, partial right scapula, a dorsal centrum, 2 damaged neural arches, 4 proximal rib fragments, a left pubic peduncle and right shaft, 2 partial calcanea, a pedal ungual phalanx and 15 caudals of varying preservation states.

These are likely of the same specimen based on them coming from a 5x2m area, they are the same size and no overlapping elements could indicate another individual present. Mateus et al. (2011) described most of the elements as Portuguese *Baryonyx*, using this new data to examine the validity of *Suchosaurus*. Arden et al. (2018) reassessed these remains as a distinct genus. Phylogenetic analysis and examination in 2022 finds that Iberian spinosaurs were more advanced than thought, naming the new genus, and was also influenced by the discovery of *Vallibonavenatrix* in 2020.

## Description

ML 1190 (fragmentary vertebrae, ribs, hips, shoulder and crania) is the holotype, of the same individual. It is known from Praia de Aguncheiras from Portugal. Autapomorphies include a dentary with one foramen in the Meckelian sulcus, a dentary with a ventral edge that is straight, laminae in the pleuocelic depression of the medio-distal caudals, a scapula with a straight anterior rim, a scapula with a reduced acromial ridge, a scapula that contacts the coracoid and occupies all of the ventral surface, a mound-like eminence at the prximal lateral pubis and a pubic apron that is thick almost the entire length of the pubis shaft. Mateus et al. (2011) described the dentary. It bears 12 alveoli, with 9 preserved. The anterior is eroded and the first socket is missing, exposing 3 foramina. The sympheseal ridges are found on the ventro-medial side, the ventral Mackelian foramen is 50 millimeters caudally from the breakage point and the lateral and medial converge anteriorly from the dorsal view. Mateus et al. mention a dentary fragment with 4 alveoli and the remnants of 2 teeth attached. The trigeminal nerve identifies this element as a dentary.

## Classification

Though previous studies recover *Iberospinus* (while it was still unnamed) outside of all spinosaurid subfamilies, based on a lack of baryonychine synapomorphies and fragmentary remains, one of the 2022 analyses places the taxon as distinct and near-to baryonychines such as *Baryonyx* and *Suchomimus*. However, another analysis places it in Spinosaurinae, one in polyotomy with *Vallibonavenatrix*, *Ichthyovenator*, *Irritator* and *Spinosaurus*. Another result shows it as outside both subfamilies. Nonetheless, they place it firmly within Spinosauridae, but find further placement unstable.

## Paleobiology

### Diet

Hendrickx et al. (2016) finds that spinosaurs could move their jaws sideways at the joint to widen the throat like in modern pterosaurs and pelicans. Since it was discovered in association with *Iguanodon* teeth, it is suggested to have been opportunistic, like other spinosaurs. It was also found to have had constant tooth eruption, which signifies a greater degree of tooth loss and recovery. Some sockets had several replacements queued, while others were using the replacement teeth. This function is not uncommon for spinosaurs. Additionally, *Iberospinus* had serrated teeth rather than the typical crocodilian-like morphology.

## Paleoecology

At the collection site, zygapophyses fragments, ribs and probable chevrons were found alongside ornithopod, turtle, pterosaur, fish, gastropod and plant material. The Papo Seco Formation represents a clastic-dominated sediment, dominated mostly by silty mud-mud deposition, lignitic horizons, gypsum and green silty clays. Medium-to-coarse typically ribbon-shaped clastic sandstones. The clastic sands are not laterally continuous along the exposure, showing ribbon sands that are isolate and laterally change into mud. This formation dates to the Barremian. Ornithopods, macronarians and theropods are known from the Papo Seco Formation, a roster of organisms similar to some of the Wealden fauna.The existence of this taxon and Vallibonavenatrix on the Iberian peninsula represents a newly-discovered trend, where multiple spinosaurid taxa are found to have coexisted. This is observed in the Wealden group and in Africa. The 2022 study found the earliest spinosaurs would have been from west Europe, where the Iberian Peninsula was previously considered; the discovery of *Iberospinus* may make this conclusion more likely.

## References

1. ↑ 1.0 1.1 1.2 1.3 1.4 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0262614
2. ↑ http://docentes.fct.unl.pt/sites/default/files/omateus/files/mateus\_et\_al\_2011\_a\_new\_specimen\_of\_the\_theropod\_dinosaur\_baryonyx\_from\_the\_early\_cretaceous\_of\_portugal\_and\_taxonomic\_validity\_of\_suchosaurus.pdf
3. ↑ https://doi.org/10.1016%2Fj.cretres.2018.08.006
4. ↑ https://doi.org/10.1007%2Fs41513-020-00138-9
5. ↑ https://doi.org/10.1016%2Fj.cretres.2018.06.013
6. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703214/
7. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703214/
8. ↑ https://www.newscientist.com/article/2308689-newly-identified-dinosaur-had-teeth-that-were-constantly-replaced/
9. ↑ https://en.wikipedia.org/wiki/Papo\_Seco\_Formation
10. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8481559/