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Fig. 5 | BMC Evolutionary Biology

Fig. 5

From: Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis, the “last” toothed birds

Fig. 5

Discriminant morphometric parameters of the studied avian and non-avian teeth. a Morphological parameters used to study tooth shape (modified from [38]). AL, apical ‘length’; CBL, crown base length; CH, crown height; CBW, crown base width (see Additional file 1: Table S1 and Additional file 2: Fig. S1). b Comparison of the studied teeth with published data on specimens of the non-avian theropod genus Richardoestesia [25] reveals that attested and putative Late Cretaceous birds overlap with non-avian specimens in terms of height vs. length or width, with comparable variance. c The slight difference between teeth of non-avian taxa otherwise morphologically close to avian ones, such as Richardoestesia [38], and teeth positively identified as avian (our Hesperornis and Ichthyornis specimens) corresponds to the degree of crown base labio-lingual enlargement relative to height, i.e., ratio of crown width at the level of the neck versus height. The tooth TMP 1989.103.0025 is here considered as presumed avian (eventhough this is debated, with some recent publications proposing R. isosceles; see Results and Discussion)

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