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A new species of the basal "kangaroo" Balbaroo and a re-evaluation of stem macropodiform interrelationships.

Black KH, Travouillon KJ, Den Boer W, Kear BP, Cooke BN, Archer M - PLoS ONE (2014)

Bottom Line: Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis.Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws.All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

View Article: PubMed Central - PubMed

Affiliation: School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.

ABSTRACT
Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal "kangaroo", and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade--Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

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Related in: MedlinePlus

Balbaroo nalima sp. nov. Holotype QM F36295.(A) left lateral view and (B) right lateral view (B). Abbreviations: as, alisphenoid; C, upper canine; eam, external auditory meatus; ec, ectotympanic; fr, frontal; fro, foramen rotundum; ioc, infraorbital canal; iof, infraorbital foramen; ju, jugal; lac, lacrimal; lacf, lacrimal foramen; M1-M4, upper molar one to molar four; ma, mastoid; map, mastoid process; mx, maxilla; oc, occipital condyle; os, orbitosphenoid; P3, upper third premolar; pa, parietal; pal, palatine; pgp, postglenoid process; pmx, premaxilla; pt, pterygoid; sfo, secondary foramen ovale; smaf, stylomastoid foramen; smf, suprameatal foramen; sof, sphenorbital fissure; spf, sphenopalatine foramen; sq, squamosal. Scale bar equals 10 mm.
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pone-0112705-g008: Balbaroo nalima sp. nov. Holotype QM F36295.(A) left lateral view and (B) right lateral view (B). Abbreviations: as, alisphenoid; C, upper canine; eam, external auditory meatus; ec, ectotympanic; fr, frontal; fro, foramen rotundum; ioc, infraorbital canal; iof, infraorbital foramen; ju, jugal; lac, lacrimal; lacf, lacrimal foramen; M1-M4, upper molar one to molar four; ma, mastoid; map, mastoid process; mx, maxilla; oc, occipital condyle; os, orbitosphenoid; P3, upper third premolar; pa, parietal; pal, palatine; pgp, postglenoid process; pmx, premaxilla; pt, pterygoid; sfo, secondary foramen ovale; smaf, stylomastoid foramen; smf, suprameatal foramen; sof, sphenorbital fissure; spf, sphenopalatine foramen; sq, squamosal. Scale bar equals 10 mm.

Mentions: Description is based on the Holotype QM F36295 (Figs 2, 7–8), an adult skull with fully erupted P3-M4. The left P3 and right P3-M4 have intact crowns. The left C1 is missing tip of crown, left M1 missing posterolingual tooth corner, left M2 missing all of the crown, left M3-4 missing lingual face of the crown. Skull near complete missing only the nasals, the dorsal surfaces of the left and right maxillae and left premaxillae, and most of the left zygomatic arch. The unworn dentition and the distinct, unobliterated sutures (particularly those of the basicranium and occiput) suggest the individual was a relatively young adult.


A new species of the basal "kangaroo" Balbaroo and a re-evaluation of stem macropodiform interrelationships.

Black KH, Travouillon KJ, Den Boer W, Kear BP, Cooke BN, Archer M - PLoS ONE (2014)

Balbaroo nalima sp. nov. Holotype QM F36295.(A) left lateral view and (B) right lateral view (B). Abbreviations: as, alisphenoid; C, upper canine; eam, external auditory meatus; ec, ectotympanic; fr, frontal; fro, foramen rotundum; ioc, infraorbital canal; iof, infraorbital foramen; ju, jugal; lac, lacrimal; lacf, lacrimal foramen; M1-M4, upper molar one to molar four; ma, mastoid; map, mastoid process; mx, maxilla; oc, occipital condyle; os, orbitosphenoid; P3, upper third premolar; pa, parietal; pal, palatine; pgp, postglenoid process; pmx, premaxilla; pt, pterygoid; sfo, secondary foramen ovale; smaf, stylomastoid foramen; smf, suprameatal foramen; sof, sphenorbital fissure; spf, sphenopalatine foramen; sq, squamosal. Scale bar equals 10 mm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4237356&req=5

pone-0112705-g008: Balbaroo nalima sp. nov. Holotype QM F36295.(A) left lateral view and (B) right lateral view (B). Abbreviations: as, alisphenoid; C, upper canine; eam, external auditory meatus; ec, ectotympanic; fr, frontal; fro, foramen rotundum; ioc, infraorbital canal; iof, infraorbital foramen; ju, jugal; lac, lacrimal; lacf, lacrimal foramen; M1-M4, upper molar one to molar four; ma, mastoid; map, mastoid process; mx, maxilla; oc, occipital condyle; os, orbitosphenoid; P3, upper third premolar; pa, parietal; pal, palatine; pgp, postglenoid process; pmx, premaxilla; pt, pterygoid; sfo, secondary foramen ovale; smaf, stylomastoid foramen; smf, suprameatal foramen; sof, sphenorbital fissure; spf, sphenopalatine foramen; sq, squamosal. Scale bar equals 10 mm.
Mentions: Description is based on the Holotype QM F36295 (Figs 2, 7–8), an adult skull with fully erupted P3-M4. The left P3 and right P3-M4 have intact crowns. The left C1 is missing tip of crown, left M1 missing posterolingual tooth corner, left M2 missing all of the crown, left M3-4 missing lingual face of the crown. Skull near complete missing only the nasals, the dorsal surfaces of the left and right maxillae and left premaxillae, and most of the left zygomatic arch. The unworn dentition and the distinct, unobliterated sutures (particularly those of the basicranium and occiput) suggest the individual was a relatively young adult.

Bottom Line: Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis.Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws.All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

View Article: PubMed Central - PubMed

Affiliation: School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.

ABSTRACT
Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal "kangaroo", and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade--Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.

Show MeSH
Related in: MedlinePlus