The origins of neural spine elongation in iguanodontian dinosaurs and the osteology of a new sail-back styracosternan (Dinosauria: Ornithischia) from the Lower Cretaceous Wealden Group of England

The Wealden Group of southern England was deposited during the late Berriasian into the early Aptian. It records a critical time in the development of iguanodontian dinosaur diversity, from the low levels of the Jurassic to the higher levels in the Aptian and Albian. A new iguanodontian dinosaur, Istiorachis macarthurae gen. et sp. nov. from the Wessex Formation (Wealden Group) of the Isle of Wight, exhibits hyperelongation of the dorsal and caudal neural spines, suggesting that it possessed a possible sail structure. Ancestral state reconstruction for the relative height of dorsal neural spines in iguanodontians reveals that modest elongation began with Ankylopollexia in the Late Cretaceous and elongation became established during the Cenomanian stage of the Late Cretaceous, albeit with widely disparate values. Hyperelongation of neural spines occurred sporadically throughout the Cretaceous, being most frequently recorded in the Barremian and early Aptian. Possible explanations for neu..., , # Data from: The origins of neural spine elongation in iguanodontian dinosaurs and the osteology of a new sail-back styracosternan (Dinosauria: Ornithischia) from the Lower Cretaceous Wealden Group of England

Dataset DOI: [10.5061/dryad.v6wwpzh78](10.5061/dryad.v6wwpzh78)

## Description of the data and file structure

GENERAL INFORMATION

Data set for: The origins of neural spine elongation in iguanodontian dinosaurs and the osteology of a new sail-back styracosternan (Dinosauria: Ornithischia) from the Lower Cretaceous Wealden Group of England.

Jeremy A. F. Lockwood

[http://orchid](http://orchid) .org/000-0002-3233-0819

Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, London SW7 5BD, UK.

[[e-mail]](mailto:[e-mail])

Susannah C. R. Maidment

[http://orchid](http://orchid) .org/000-0002-7741-2500

Fossil Reptiles, Amphibians and Birds Section, Natural History Museum, London SW7 5BD, UK.

[[e-mail]](mailto:susannah.ma...,