(en) Lee, Michael SY. et al. (2014). Morphological Clocks in Paleontology, and a Mid-Cretaceous Origin of Crown Aves. Systematic Biology63 (1): 442–449 (Oxford Journals). PMID24449041. DOI: 10.1093/sysbio/syt110.
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(en) Lee, Michael SY. et al. (2014). Morphological Clocks in Paleontology, and a Mid-Cretaceous Origin of Crown Aves. Systematic Biology63 (1): 442–449 (Oxford Journals). PMID24449041. DOI: 10.1093/sysbio/syt110.