Media 000461726: Cranium And Mandible [Mesh] [Photogram]
Represents:
Biological Specimen
In Collection

GENERAL DETAILS

Media ID
000461726
Media type
Mesh
Object element or part
Cranium and mandible
Side
Right
Orientation
Internal view
Short description
Internal view of cranium and mandible of Ramasyia magna
Full description
This specimen is reported and described in: Louys, J., Duval,M., Beck, R.M.D., Pease, E., Sobbe, I., Sands, N., Price, G.J. accepted 1/9/2022). Cranial remains of Ramsayia magna from the Late Pleistocene of Australia and the evolution of gigantism in wombats (Vombatidae; Marsupialia). Palaeontology. Abstract: Giant wombats (defined here as body mass ≥ 70 kg) are found in the genera Phascolonus, Ramsayia, and perhaps also Sedophascolomys. Of these, Ramsayia is the currently the most poorly known, having been described from fragmentary mandibular and cranial fragments. Here, we report the most complete cranial remains attributable to the genus, identified as the species R. magna. The remains provide new important insights into the anatomy of the species and the evolutionary adaptations to gigantism in Vombatidae. We record parietal sinuses in a vombatid for the first time, an adaptation to increased skull size relative to the braincase. The presence of a prominent premaxillary spine may indicate the species possessed a large, fleshy nose. Both of features are convergent on other large-bodied, non-vombatid extinct megaherbivores of Australia such as Diprotodon optatum. We use the cranial remains to examine the phylogenetic relationships of the giant wombats to other vombatids. Phylogenetic analysis using maximum parsimony and Bayesian inference indicates that Phascolomys, Ramsayia, and Sedophascolomys form a clade, suggesting a single origin of gigantism within Vombatidae. This origin may have been related to the exploitation of poor-quality foods by these taxa, and preceded the extreme specialisations observed in the incisor and cranial anatomy of the giant wombats. U-series and combined U-series and Electron Spin Resonance (ESR) dating methods were applied to one fossil tooth. All sources of uncertainty considered, age calculations systematically correlate the fossil remains to Marine Isotope Stage 5, and an age of approximately 80,000 years can be proposed for this specimen. With only a single well dated occurrence for this taxon, it is currently impossible to determine when and why R. magna became extinct.
Creator
Gilbert Price
Date created
July 20, 2022
Date uploaded
September 20, 2022

FILE OBJECT DETAILS

File format(s)
text/prs.wavefront-obj
File size
11.6 MB
Points
245,799
Polygons
490,879
Map type
--
UV coordinates
True
Vertex color
False
Bounding box dimensions
6.935, 5.430, 6.624
Centroid coordinates
0.240, -0.103, -10.795
Units of point coordinates
--

IMAGE ACQUISITION AND PROCESSING AT A GLANCE

Number of parent media
1
Number of processing events
1 (0 steps)
Modality
Photogrammetry
Device
Nikon D5200, Palaeo Lab at The University of Queensland (University of Queensland)

OWNERSHIP AND PERMISSIONS

Data managed by
Data uploaded by
Download permission
Publish with Open Download
Download reviewer
IP holder
Gilbert Price
Morphosource use agreement type
Standard
Permits commercial use
Commercial Use Not Permitted
Permits 3D use
3D Printing Permitted
Required archival of published derivatives
Encouraged But Not Required
Funding attribution
--
Publisher
--
Cite as
--
Media preview mode
Interactive/Embeddable
Additional usage agreement
None

IDENTIFIERS AND EXTERNAL LINKS

MorphoSource ARK
MorphoSource DOI
External identifier
--
External media URL
--

IMAGE ACQUISITION AND PROCESSING IN DETAIL

STEP 1: IMAGE ACQUISITION

Imaging Details

Modality
Photogrammetry
Device
Nikon D5200
Device facility
Palaeo Lab at The University of Queensland (University of Queensland)
Creator
Price, Gilbert J.
Date
July 20, 2022
Software
Agisoft Metashape
Description
This specimen is reported and described in: Louys, J., Duval,M., Beck, R.M.D., Pease, E., Sobbe, I., Sands, N., Price, G.J. accepted 1/9/2022). Cranial remains of Ramsayia magna from the Late Pleistocene of Australia and the evolution of gigantism in wombats (Vombatidae; Marsupialia). Palaeontology. Abstract: Giant wombats (defined here as body mass ≥ 70 kg) are found in the genera Phascolonus, Ramsayia, and perhaps also Sedophascolomys. Of these, Ramsayia is the currently the most poorly known, having been described from fragmentary mandibular and cranial fragments. Here, we report the most complete cranial remains attributable to the genus, identified as the species R. magna. The remains provide new important insights into the anatomy of the species and the evolutionary adaptations to gigantism in Vombatidae. We record parietal sinuses in a vombatid for the first time, an adaptation to increased skull size relative to the braincase. The presence of a prominent premaxillary spine may indicate the species possessed a large, fleshy nose. Both of features are convergent on other large-bodied, non-vombatid extinct megaherbivores of Australia such as Diprotodon optatum. We use the cranial remains to examine the phylogenetic relationships of the giant wombats to other vombatids. Phylogenetic analysis using maximum parsimony and Bayesian inference indicates that Phascolomys, Ramsayia, and Sedophascolomys form a clade, suggesting a single origin of gigantism within Vombatidae. This origin may have been related to the exploitation of poor-quality foods by these taxa, and preceded the extreme specialisations observed in the incisor and cranial anatomy of the giant wombats. U-series and combined U-series and Electron Spin Resonance (ESR) dating methods were applied to one fossil tooth. All sources of uncertainty considered, age calculations systematically correlate the fossil remains to Marine Isotope Stage 5, and an age of approximately 80,000 years can be proposed for this specimen. With only a single well dated occurrence for this taxon, it is currently impossible to determine when and why R. magna became extinct.
Imaging event description attachment
Imaging event reference attachment
None
Filter
--
Lens
Nikon AF-S Micro 40mm
Other details
--

STEP 2: IMAGE PROCESSING

Raw Media 000461723: Cranium And Mandible [PhotogrammetryImageSeries] [Photogram] was processed to create derived Media 000461726: Cranium And Mandible [Mesh] [Photogram] (this media).

Processing Details

Creator
Gilbert Price
Date processed
July 20, 2022
Software
Agisoft Metashape Professional
Description
This specimen is reported and described in: Louys, J., Duval,M., Beck, R.M.D., Pease, E., Sobbe, I., Sands, N., Price, G.J. accepted 1/9/2022). Cranial remains of Ramsayia magna from the Late Pleistocene of Australia and the evolution of gigantism in wombats (Vombatidae; Marsupialia). Palaeontology. Abstract: Giant wombats (defined here as body mass ≥ 70 kg) are found in the genera Phascolonus, Ramsayia, and perhaps also Sedophascolomys. Of these, Ramsayia is the currently the most poorly known, having been described from fragmentary mandibular and cranial fragments. Here, we report the most complete cranial remains attributable to the genus, identified as the species R. magna. The remains provide new important insights into the anatomy of the species and the evolutionary adaptations to gigantism in Vombatidae. We record parietal sinuses in a vombatid for the first time, an adaptation to increased skull size relative to the braincase. The presence of a prominent premaxillary spine may indicate the species possessed a large, fleshy nose. Both of features are convergent on other large-bodied, non-vombatid extinct megaherbivores of Australia such as Diprotodon optatum. We use the cranial remains to examine the phylogenetic relationships of the giant wombats to other vombatids. Phylogenetic analysis using maximum parsimony and Bayesian inference indicates that Phascolomys, Ramsayia, and Sedophascolomys form a clade, suggesting a single origin of gigantism within Vombatidae. This origin may have been related to the exploitation of poor-quality foods by these taxa, and preceded the extreme specialisations observed in the incisor and cranial anatomy of the giant wombats. U-series and combined U-series and Electron Spin Resonance (ESR) dating methods were applied to one fossil tooth. All sources of uncertainty considered, age calculations systematically correlate the fossil remains to Marine Isotope Stage 5, and an age of approximately 80,000 years can be proposed for this specimen. With only a single well dated occurrence for this taxon, it is currently impossible to determine when and why R. magna became extinct.
Description attachment

Media produced by this event on MorphoSource


Media 000461726: Cranium And Mandible [Mesh] [Photogram] (this media)