Trinacromerum is an extinct genus of sauropterygian reptile belonging to the plesiosaur suborder. Specimens that lived during the Late Cretaceous period have been discovered in what is now modern Kansas and Manitoba.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0