School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK.
Biol Lett. 2021 Jul;17(7):20210168. doi: 10.1098/rsbl.2021.0168. Epub 2021 Jul 14.
The ability of palaeontologists to correctly diagnose and classify new fossil species from incomplete morphological data is fundamental to our understanding of evolution. Different parts of the vertebrate skeleton have different likelihoods of fossil preservation and varying amounts of taxonomic information, which could bias our interpretations of fossil material. Substantial previous research has focused on the diversity and macroevolution of non-avian theropod dinosaurs. Theropods provide a rich dataset for analysis of the interactions between taxonomic diagnosability and fossil preservation. We use specimen data and formal taxonomic diagnoses to create a new metric, the Likelihood of Diagnosis, which quantifies the diagnostic likelihood of fossil species in relation to bone preservation potential. We use this to assess whether a taxonomic identification bias impacts the non-avian theropod fossil record. We find that the patterns of differential species abundance and clade diversity are not a consequence of their relative diagnosability. Although there are other factors that bias the theropod fossil record that are not investigated here, our results suggest that patterns of relative abundance and diversity for theropods might be more representative of Mesozoic ecology than often considered.
古生物学家正确诊断和分类新的化石物种的能力，对于我们理解进化至关重要。脊椎动物骨骼的不同部位具有不同的化石保存可能性和不同数量的分类学信息，这可能会使我们对化石材料的解释产生偏差。大量先前的研究集中在非鸟类兽脚亚目恐龙的多样性和宏观进化上。兽脚亚目为分析分类可诊断性与化石保存之间的相互作用提供了丰富的数据。我们使用标本数据和正式的分类诊断来创建一个新的度量标准，即诊断可能性的可能性，该标准量化了与骨骼保存潜力相关的化石物种的诊断可能性。我们使用它来评估分类识别偏差是否会影响非鸟类兽脚亚目恐龙的化石记录。我们发现，物种丰度和支系多样性的差异模式不是其相对可诊断性的结果。尽管还有其他因素会影响兽脚亚目恐龙的化石记录，但我们的研究结果表明，兽脚亚目恐龙的相对丰度和多样性模式可能比通常认为的更能代表中生代的生态。
