Cariocecus, new hadrosauroid from Lower Cretaceous of Portugal

[Ben Creisler]

Ben Creisler

bcre...@gmail.com

A new paper:

===

Cariocecus bocagei gen. et sp. nov.

Filippo Bertozzo, Bruno Camilo, Ricardo Araújo, Fabio Manucci, José Carlos Kullberg, Donald G. Cerio, Victor Feijó de Carvalho, Pedro Marrecas, Silvério D. Figueiredo & Pascal Godefroit (2025)

Cariocecus bocagei, a new basal hadrosauroid from the Lower Cretaceous of Portugal

Journal of Systematic Palaeontology 23(1): 2536347 

doi: https://doi.org/10.1080/14772019.2025.2536347

https://www.tandfonline.com/doi/full/10.1080/14772019.2025.2536347

 

https://zoobank.org/urn:lsid:zoobank.org:pub:C02A3840-F7A5-44FA-882D-4403933EAB4C

 

In Portugal, iguanodontian dinosaurs are mostly known from the Late Jurassic of the Lourinhã Formation and are represented by dryosaurids and basal styracosternans. The Early Cretaceous record of iguanodontians in Portugal is scarce in comparison, with scattered and uninformative remains referred to Styracosterna indet. Here, we describe SHN.832, the first iguanodontian skull from Portugal, named Cariocecus bocagei gen. nov. sp. nov. The specimen was found in Praia do Areia do Mastro (Cabo Espichel, Sesimbra) in the Papo Seco Formation (lower Barremian), and comprises the right side of the skull, part of the skull vault and a nearly complete basicranium. Cariocecus bocagei is diagnosed based on autapomorphies such as the co-ossified maxillo-jugal complex and the trilobated shape of the supraoccipital. The phylogenetic analysis retrieves C. bocagei as a basal hadrosauroid in a clade with Comptonatus chasei and Brighstoneus simmondsi. Our biogeographical analysis emphasizes the effects of insular endemism during the Hauterivian–Aptian range in the European regions. We show that Iguanodontia originated in South America, and through a dispersal event towards North America during the Upper Jurassic, expanded their latitudinal range. Cariocecus and other early-diverging iguanodontians emerged during an eastward dispersal event in the Lower Cretaceous. We reconstructed the endocast, cranial nerves and inner ear of Cariocecus via segmentation of micro-computed tomography scanning, showing similarities with other Hadrosauriformes such as Iguanodon and Proa. We propose the most detailed inner ear soft-tissue reconstruction for a dinosaur so far, including the macula and sub-branches of the vestibulocochlear nerve, supported by the extant phylogenetic bracket. Based on the unossified suture of the cranial elements, we hypothesize that SHN.832 had not yet reached full skeletal maturity, and our restoration suggests a total skull length of about 45 cm. The supraorbital membrane was reconstructed based on the well-preserved supraorbital bone and comparison with modern taxa.

====

 

[Tim Williams]

This new ornithopod _Cariocecus_ is featured here: www.naturalsciences.be/en/science/news/new-iguanodon-species-discovered-in-portugal

The paper by Bertozzo et al. refers to a specimen RBINS R51 under the name ‘_Mantellisaurus atherfieldensis_’.   For example as in: "_Mantellisaurus_ and _Iguanodon_ nest together, but ‘_Mantellisaurus atherfieldensis_’ RBINS R51 is not yet considered in this analysis, as a re-evaluation of the specimen is under consideration."

I thought RBINS R51 was the holotype of _Iguanodon bernissartensis_ - a complete and articulated skeleton.  Is 'RBINS R51' a typo, and the authors actually mean RBINS 1551 - the holotype of _Dollodon bampingi_ (Paul, 2008), which was subsequently referred to _Mantellisaurus atherfieldensis_ (e.g., Norman, 2010; McDonald, 2012)?  

--
You received this message because you are subscribed to the Google Groups "Dinosaur Mailing Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to DinosaurMailingG...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAMR9O1KqgwsCX-9u0hyXPOr%2BPNUnMaJLuDuCMdxWkFnR_sXaBA%40mail.gmail.com.

[Alessandro Marisa]

Tim is right the specimen RBINS R51 is effectively the Holotype specimen of Iguanodon bernissartensis actually on display in the Dinosaur gallery of the Royal Belgian Institute of Natural Sicences in Brussels, Belgium. I think that Bertozzo et al. refers to the specimen RBINS 1551 the Holotype of "Dollodon" bampingi (Paul, 2008) that in my opinion needed a re-evaluation. At the moment the best way for coding Mantellisaurus atherfieldensis is to use only the Holotype specimen NHMUK PV R5764 recently well described by Bonsor et al. (2023) and use RBINS 1551 as a separate OTUs as I'm doing in my Hadrosauroidea analysis.

Alessandro

[Gregory Paul]

And in Bonsor's masters thesis 1551 scores well away from M. ather. in all his cladograms -- somewhat to my surprise how far away. And 1551 will soon be properly described (by scanning, delicate specimen cannot be touched) and I have good reason the think it will be as Dollodon -- it is probably a few million year older than M. a. duh. And Bonsor diagnoses Huxleysaurus, and S. pauli;) 

GSPaul 

https://groups.google.com/d/msgid/DinosaurMailingGroup/059d96d4-e0e1-4dce-abfd-eb7b4f7612cen%40googlegroups.com

.

[Mickey Mortimer]

If Paul is referring to his 2023 PhD thesis available here- https://researchportal.bath.ac.uk/en/studentTheses/the-taxonomy-and-systematics-of-the-iguanodontian-dinosaurs , then it should be noted the resolved cladograms (figures 6.5-6.7) are all implied weights, so that certain characters were weighted more than others. Unfortunately, Bonsor made the same mistake Raven et al. did for thyreophorans and did not bother to prune taxa a posteriori to see what topology his equal weights tree (figure 6.4) actually has, so what I would consider his 'true' results, as in using the same methodology as 99% of other Mesozoic dinosaur analyses, as yet unreported. People have to stop using implied weights as a shortcut to get resolved trees. There's only 30 MPTs and some of them are only different outside Ankylopollexia or near Hadrosauridae, so I bet it's just a few unstable taxa causing that big iguanodontid-grade polytomy.

Mickey Mortimer

[Ben Creisler]

The pdf is now free:

Filippo Bertozzo, Bruno Camilo, Ricardo Araújo, Fabio Manucci, José Carlos Kullberg, Donald G. Cerio, Victor Feijó de Carvalho, Pedro Marrecas, Silvério D. Figueiredo & Pascal Godefroit (2025)
Cariocecus bocagei, a new basal hadrosauroid from the Lower Cretaceous of Portugal
Journal of Systematic Palaeontology 23(1): 2536347
doi: https://doi.org/10.1080/14772019.2025.2536347
https://www.tandfonline.com/doi/full/10.1080/14772019.2025.2536347

Free pdf:
https://www.tandfonline.com/doi/epdf/10.1080/14772019.2025.2536347


Also:

Cariocecus bocagei with Dr Filippo Bertozzo of the Royal Belgian Institute of Natural Sciences.
Palaeocast Podcast Episode 170 (David Marshall)
119 min.

https://www.palaeocast.com/cariocecus-bocagei/

 

====