DOI: 10.5061/dryad.h70rxwdr8
title: Data from: Endocranial morphology of three early-diverging ceratopsians and implications for the behavior and the evolution of the endocast in ceratopsians

description: Ceratopsians underwent great changes including the shift of the locomotion
 mode, enlarged horns and frills, and increased body size. These changes
 are along with the changes in endocranial morphology and ecology such as
 the decrease of the flocculus, the hearing range, the olfactory ratio, and
 the Reptile Encephalization Quotient. However, the endocranial structures
 and associated ecology of the earliest ceratopsians are still unknown.
 Here, we reconstructed the endocasts of three early-diverging ceratopsians
 including the Late Jurassic Yinlong, and the Early Cretaceous Liaoceratops
 and Psittacosaurus. These ceratopsians display prominent flocculus, large
 and separate olfactory bulbs, long and high anterior semicircular canal,
 and long endosseous cochlear duct. Unlike Liaoceratops and Psittacosaurus,
 Yinlong exhibits relatively stocky semicircular canals and small
 flocculus. In Ceratopsia, the evolutional patterns of the endocast include
 the merging and narrowing of the olfactory bulbs, the disappearing
 flocculus, the reduction of the anterior semicircular canal, the
 increasing of the angle between two vertical semicircular canals, and the
 shortening of the cochlear duct. The endocranial structures suggest
 early-diverging ceratopsians had a high olfactory acuity and were adapted
 to hearing high frequencies, unlike the condition of late-diverging
 ceratopsians with lower olfactory acuity and hearing frequency. Reptile
 Encephalization Quotient suggests that Yinlong and Psittacosaurus were
 more encephalized than most extant reptiles and late-diverging
 ceratopsians. The angle of the lateral semicircular canal suggests that
 heads in ceratopsians display a transition from an upward posture to a
 downward posture. The relatively upward head posture indicates that
 early-diverging ceratopsians could feed more selectively such as to eat
 some leaves.
description: # Data from: Endocranial morphology of three early-diverging ceratopsians
 and implications for the behavior and the evolution of the endocast in
 ceratopsians Contact: Fenglu Han School of Earth Sciences, China
 University of Geosciences, Wuhan, Hubei, China
 [hanfl@cug.edu.cn](mailto:hanfl@cug.edu.cn) Data Files: 1. CUGW_VH104.zip
 Desciption: The zip file contains raw micro-CT scans of the braincase of
 CUGW VH104 as .BMP file format. Media type: CTimageSeries File format: BMP
 Specimen number: CUGW_VH104 Full description: Psittacosaurus
 lujiatunensis, the skull cropped to the braincase regions Image width:
 1015 Image height: 1352 Number of images in set: 1199 Color depth: 16
 Pixel size: 49.2519 μm Modality: X-Ray Computed Tomography Device: a 300
 kV micro-computed tomography instrument (Phoenix Vtomex M) and the
 detector (Dynamic41-100) 2. IVPP_V12738.zip Desciption: The zip file
 contains raw micro-CT scans of the braincase of IVPP V12738 as .BMP file
 format. Media type: CTimageSeries File format: bmp Specimen number: IVPP
 V12738 Full description: Liaoceratops yanzigouensis, the skull cropped to
 the braincase regions Image width: 1058 Image height: 1084 Number of
 images in set: 1130 Color depth: 16 Pixel size: 42.30 μm Modality: X-Ray
 Computed Tomography Device: a 300 kV micro-computed tomography instrument
 (Phoenix Vtomex M) and the detector (Dynamic41-100) 3. IVPP V18637.zip
 Desciption: The zip file contains raw micro-CT scans of the braincase of
 IVPP V18637 as .BMP file format. Media type: CTimageSeries File format:
 bmp Specimen number: IVPP V18637 Full description: Yinlong downsi, the
 skull cropped to the braincase regions Image width: 658 Image height: 602
 Number of images in set: 779 Color depth: 16 Pixel size: 160 μm Modality:
 X-Ray Computed Tomography Device: a 450 kV micro-computed tomography
 instrument (450 ICT) Scanning on IVPP V18637 was carried out using a 450
 kV micro-computed tomography instrument (450 ICT) at the Key Laboratory of
 Vertebrate Evolution and Human Origins. | Taxa | Specimen number |
 Scanning voltage | Scanning current | Resolution (µm) | | :------------- |
 :-------------- | :--------------- | :--------------- | :-------------- |
 | Yinlong | IVPP V18637 | 430 kV | 1500 µA | 160 | | Psittacosaurus | CUGW
 VH104 | 250 kV | 310 µA | 49.25 | | Liaoceratops | IVPP V12738 | 140 kV |
 100 µA | 42.30 |