How can we articulate extinct animals in a hypothesis state

The species recognition hypothesis explains exaggerated structures in non-avialan dinosaurs better than sexual selection does

Several hypotheses have been proposed to explain “bizarre structures” in dinosaurs and other extinct animals (e.g., mechanical function and several kinds of intra- and interspecific display). Recent evidence and tests for species recognition as a possible driver of these structures have been proposed, in particular as an alternative to traditional hypotheses of function and sexual selection, which have fallen short. Advocates of sexual selection and mechanical function have advanced untested hypotheses claiming that species recognition cannot be an important process in evolution. We address these claims and show that they are based on misreading of the evidence and of previous literature. We also acknowledge that there have been historically differing definitions of sexual selection, which have greatly impeded understanding of the whole phenomenon of mate attraction and choice. Particularly in fossil animals, it is impossible to accept any hypothesis as the “default” that does not require evidence or testing to establish it.

Explanation:

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation: