Fossilization can mislead analyses of phenotypic disparity

Area of Science:

• Paleontology
• Evolutionary Biology
• Biogeography

Background:

• Morphological disparity analyses integrate living and fossil taxa to study phenotypic variation over time.
• Taphonomic processes cause non-random data loss in fossil records, potentially impacting disparity perceptions.

Purpose of the Study:

• To investigate how random and structured data loss affect measures of morphological disparity.
• To evaluate the influence of taphonomic data loss on clade disparity and commonly used disparity indices.
• To determine the role of extant taxa and exceptionally preserved fossils in mitigating data loss distortions.

Main Methods:

• Simulating and empirically degrading data to characterize changes in disparity measures.
• Employing various distance metrics and disparity indices to assess distortions.
• Incorporating extant taxa and exceptionally preserved fossils as reference points.

Main Results:

• Both random and structured data loss significantly distort clade disparity.
• The magnitude and direction of distortions vary depending on the distance metrics and disparity indices used.
• Including extant taxa and exceptionally preserved fossils effectively mitigates these distortions.

Conclusions:

• Data loss due to taphonomy can lead to misinterpretations of morphological disparity.
• Extant taxa and exceptionally preserved fossils are crucial for accurate disparity analyses and evolutionary simulations.
• Caution is advised when extrapolating patterns from incomplete datasets, as they may only represent sampled traits.