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An Immature Pachyrhinosaurus perotorum (Dinosauria: Ceratopsidae) Nasal Reveals Unexpected Complexity of Craniofacial Ontogeny and Integument in Pachyrhinosaurus.

Fiorillo AR, Tykoski RS - PLoS ONE (2013)

Bottom Line: The combination of morphologies in the new specimen suggests either an additional stage of development should be recognized in the ontogeny of the nasal boss of Pachyrhinosaurus, or that the ontogenetic pathway of nasal boss development in P. perotorum was notably different from that of P. lakustai.Additionally, the presence of a distinct basal sulcus and the lateral palisade texture on the nasal horn of the specimen described here indicate that a thick, cornified horn sheath was present well before the formation of a dorsal cornified pad.A separate rugose patch on the nasal well posterior to the nasal horn is evidence for a cornified integumentary structure, most likely a thick cornified pad, on the posterior part of the nasal separate from the nasal horn prior to the onset of nasal boss formation in P. perotorum.

View Article: PubMed Central - PubMed

Affiliation: Perot Museum of Nature and Science, Dallas, Texas, United States of America.

ABSTRACT
A new specimen attributable to an immature individual of Pachyrhinosaurus perotorum (Dinosauria, Ceratopsidae) from the Kikak-Tegoseak Quarry in northern Alaska preserves a mix of features that provides refinement to the sequence of ontogenetic stages and transformations inferred for the development of the nasal boss in Pachyrhinosaurus. The new specimen consists of an incomplete nasal that includes the posterior part of the nasal horn, the dorsal surface between the horn and the left-side contacts for the prefrontal and frontal, and some of the left side of the rostrum posteroventral to the nasal horn. The combination of morphologies in the new specimen suggests either an additional stage of development should be recognized in the ontogeny of the nasal boss of Pachyrhinosaurus, or that the ontogenetic pathway of nasal boss development in P. perotorum was notably different from that of P. lakustai. Additionally, the presence of a distinct basal sulcus and the lateral palisade texture on the nasal horn of the specimen described here indicate that a thick, cornified horn sheath was present well before the formation of a dorsal cornified pad. A separate rugose patch on the nasal well posterior to the nasal horn is evidence for a cornified integumentary structure, most likely a thick cornified pad, on the posterior part of the nasal separate from the nasal horn prior to the onset of nasal boss formation in P. perotorum.

No MeSH data available.


Related in: MedlinePlus

Artistic rendering of Pachyrhinosaurus perotorum engaged in head-butting/pushing behavior.In the first description of Pachryhinosaurus by Sternberg [1], he speculated that the enlarged nasal boss in the taxon might have been used in head battering or pushing behavior, an idea emphasized by this image of two Pachyrhinosaurus perotorum sparring with their craniofacial bosses, while a third looks on. Artwork by K. Carr.
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pone-0065802-g001: Artistic rendering of Pachyrhinosaurus perotorum engaged in head-butting/pushing behavior.In the first description of Pachryhinosaurus by Sternberg [1], he speculated that the enlarged nasal boss in the taxon might have been used in head battering or pushing behavior, an idea emphasized by this image of two Pachyrhinosaurus perotorum sparring with their craniofacial bosses, while a third looks on. Artwork by K. Carr.

Mentions: In addition to descriptions of osteology and inferences of ontogeny of the craniofacial bosses in Pachyrhinosaurus, these massive and visually bizarre structures have prompted speculation and hypotheses of function, behavior and soft-tissue reconstruction in this and related centrosaurine taxa. It was first suggested by Sternberg [1] that the craniofacial bosses in Pachyrhinosaurus were an adaptation for head-butting or head-pushing behavior (Figure 1), and that the bosses were covered in life by cornified skin. More radical reconstructions of Pachyrhinosaurus envisioned a large, rhinoceros-like dermal horn arising from the nasal boss, although such a structure was viewed with skepticism by others [4], [10], [11], [12].


An Immature Pachyrhinosaurus perotorum (Dinosauria: Ceratopsidae) Nasal Reveals Unexpected Complexity of Craniofacial Ontogeny and Integument in Pachyrhinosaurus.

Fiorillo AR, Tykoski RS - PLoS ONE (2013)

Artistic rendering of Pachyrhinosaurus perotorum engaged in head-butting/pushing behavior.In the first description of Pachryhinosaurus by Sternberg [1], he speculated that the enlarged nasal boss in the taxon might have been used in head battering or pushing behavior, an idea emphasized by this image of two Pachyrhinosaurus perotorum sparring with their craniofacial bosses, while a third looks on. Artwork by K. Carr.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3686821&req=5

pone-0065802-g001: Artistic rendering of Pachyrhinosaurus perotorum engaged in head-butting/pushing behavior.In the first description of Pachryhinosaurus by Sternberg [1], he speculated that the enlarged nasal boss in the taxon might have been used in head battering or pushing behavior, an idea emphasized by this image of two Pachyrhinosaurus perotorum sparring with their craniofacial bosses, while a third looks on. Artwork by K. Carr.
Mentions: In addition to descriptions of osteology and inferences of ontogeny of the craniofacial bosses in Pachyrhinosaurus, these massive and visually bizarre structures have prompted speculation and hypotheses of function, behavior and soft-tissue reconstruction in this and related centrosaurine taxa. It was first suggested by Sternberg [1] that the craniofacial bosses in Pachyrhinosaurus were an adaptation for head-butting or head-pushing behavior (Figure 1), and that the bosses were covered in life by cornified skin. More radical reconstructions of Pachyrhinosaurus envisioned a large, rhinoceros-like dermal horn arising from the nasal boss, although such a structure was viewed with skepticism by others [4], [10], [11], [12].

Bottom Line: The combination of morphologies in the new specimen suggests either an additional stage of development should be recognized in the ontogeny of the nasal boss of Pachyrhinosaurus, or that the ontogenetic pathway of nasal boss development in P. perotorum was notably different from that of P. lakustai.Additionally, the presence of a distinct basal sulcus and the lateral palisade texture on the nasal horn of the specimen described here indicate that a thick, cornified horn sheath was present well before the formation of a dorsal cornified pad.A separate rugose patch on the nasal well posterior to the nasal horn is evidence for a cornified integumentary structure, most likely a thick cornified pad, on the posterior part of the nasal separate from the nasal horn prior to the onset of nasal boss formation in P. perotorum.

View Article: PubMed Central - PubMed

Affiliation: Perot Museum of Nature and Science, Dallas, Texas, United States of America.

ABSTRACT
A new specimen attributable to an immature individual of Pachyrhinosaurus perotorum (Dinosauria, Ceratopsidae) from the Kikak-Tegoseak Quarry in northern Alaska preserves a mix of features that provides refinement to the sequence of ontogenetic stages and transformations inferred for the development of the nasal boss in Pachyrhinosaurus. The new specimen consists of an incomplete nasal that includes the posterior part of the nasal horn, the dorsal surface between the horn and the left-side contacts for the prefrontal and frontal, and some of the left side of the rostrum posteroventral to the nasal horn. The combination of morphologies in the new specimen suggests either an additional stage of development should be recognized in the ontogeny of the nasal boss of Pachyrhinosaurus, or that the ontogenetic pathway of nasal boss development in P. perotorum was notably different from that of P. lakustai. Additionally, the presence of a distinct basal sulcus and the lateral palisade texture on the nasal horn of the specimen described here indicate that a thick, cornified horn sheath was present well before the formation of a dorsal cornified pad. A separate rugose patch on the nasal well posterior to the nasal horn is evidence for a cornified integumentary structure, most likely a thick cornified pad, on the posterior part of the nasal separate from the nasal horn prior to the onset of nasal boss formation in P. perotorum.

No MeSH data available.


Related in: MedlinePlus