How do fossil gaps limit scientists’ understanding of dinosaur evolution?

Fossil gaps significantly limit our understanding of dinosaur evolution because the fossil record is episodic and incomplete rather than continuous. These gaps hinder scientific analysis in several key ways:12

• Inability to Pinpoint Origins: Because the succession of fossil-bearing deposits is discontinuous, it is impossible to determine with certainty when the very first or last specimens of a specific organism lived.2
• Difficulty in Tracking Transitions: Evolution typically occurs through a stepwise process. Gaps in the record make it challenging to identify the precise evolutionary links between ancestral and descendant forms. As more gaps are filled, the distinct features that separate dinosaurs from other archosaurs become increasingly subtle, complicating classification.2
• Imprecise Durations: Scientists cannot precisely measure how long most dinosaur species or genera existed. Durations are often only estimated based on stratigraphic boundaries and the presumed first and last occurrences of a fossil.1
• Ecological Uncertainty: The layered nature of the record often lacks the detail needed to determine if new species actively displaced older ones through competition or predation, or if they simply expanded into niches left by declining populations.1