A tardigrade in Dominican amber.

Area of Science:

• Paleontology
• Evolutionary Biology
• Invertebrate Zoology

Background:

• Tardigrades are microscopic invertebrates known for extreme resilience.
• Their fossil record is sparse, with only two known crown-group fossils from the Cretaceous.
• Molecular data suggests tardigrade divergence predates the Cambrian period.

Purpose of the Study:

• To describe a new fossil tardigrade from Dominican amber.
• To establish the first Cenozoic fossil representative of tardigrades.
• To investigate the reasons for the tardigrade fossil record's patchiness.

Main Methods:

• Paleontological analysis of a fossil inclusion in Miocene Dominican amber.
• Morphological characterization and taxonomic classification of the specimen.
• Comparative analysis with existing tardigrade fossil and extant taxa.

Main Results:

• Discovery and description of *Paradoryphoribius chronocaribbeus* gen. et sp. nov.
• This fossil is the first unambiguous representative of the Isohypsibioidea superfamily.
• It is the first tardigrade fossil identified from the Cenozoic era.

Conclusions:

• The tardigrade fossil record may be biased towards amber inclusions due to preservation potential.
• The scarcity of pre-Cretaceous amber deposits contributes to the limited fossil record.
• *Paradoryphoribius chronocaribbeus* provides crucial insights into tardigrade Cenozoic evolution.