
ABSTRACTThis study aims to interpret the axial patterning of the crocodylian neck, and to find a potential taxonomic signal that corresponds to vertebral position. Morphological variation in the cervico‐thoracic vertebrae is compared in fifteen different crocodylian species using 3D geometric morphometric methods. Multivariate analysis indicated that the pattern of intracolumnar variation was a gradual change in shape of the vertebral series (at the parapophyses, diapophyses, prezygapohyses, and postzygapohyses), in the cervical (C3 to C9) and dorsal (D1‐D2) regions which was quite conservative among the crocodylians studied. In spite of this, we also found that intracolumnar shape variation allowed differentiation between two sub regions of the crocodylian neck. Growth is subtly correlated with vertebral shape variation, predicting changes in both the vertebral centrum and the neural spine. Interestingly, the allometric scaling for the pooled sample is equivalently shared by each vertebra studied. However, there were significant taxonomic differences, both in the average shape of the entire neck configuration (regional variation) and by shape variation at each vertebral position (positional variation) among the necks. The average neck vertebra of crocodylids is characterized by a relatively cranio‐caudally short neural arch, whereby the spine is relatively longer and pointed orthogonal to the frontal plane. Conversely, the average vertebra in alligatorids has cranio‐caudally longer neural spine and arch, with a relatively (dorso‐ventrally) shorter spine. At each vertebral position there are significant differences between alligatorids and crocodylids. We discuss that the delayed timing of neurocentral fusion in Alligatoridae possibly explains the observed taxonomic differences. Anat Rec, 297:1278–1291, 2014. © 2014 Wiley Periodicals, Inc.
Male, GEOMETRIC MORPHOMETRICS, Alligators and Crocodiles, Principal Component Analysis, NECK ORGANIZATION, Anatomic Variation, CROCODYLIDAE, Thoracic Vertebrae, Imaging, Three-Dimensional, https://purl.org/becyt/ford/1.6, ALLIGATORIDAE, INTERSPECIFIC ALLOMETRY, Cervical Vertebrae, Animals, https://purl.org/becyt/ford/1
Male, GEOMETRIC MORPHOMETRICS, Alligators and Crocodiles, Principal Component Analysis, NECK ORGANIZATION, Anatomic Variation, CROCODYLIDAE, Thoracic Vertebrae, Imaging, Three-Dimensional, https://purl.org/becyt/ford/1.6, ALLIGATORIDAE, INTERSPECIFIC ALLOMETRY, Cervical Vertebrae, Animals, https://purl.org/becyt/ford/1
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 16 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
