The article seem quite good at first glance. I have contributed in plenty of geology articles so I can see it uses adequate terminology but it need to trimmed down at places to not be overly technical.
some things I think need to be clarified:
Mean annual temperatures are those estimated for environment where fossils deposited. That should be clear as to avoid confusion with present-day climate.
Etymology section way too short. It should be integrated somewhere else. Also etymology is also mentioned in "description".
There is an excess of pictures that lead to stacking, producing even blank spaces.
There is one obvious fact issue: the basin does not contain fossils of the first Neotropic forest, it contains the oldest known fossil assemblage (as of 2009) representing a Neotropical forest. Older Neotropical forests are not only possible but also likely.
Various references have problems.
Reference no. 5, "The 10 biggest coal mines in the world", is not properly formatted.
Reference no. 6, "Cerrejón", is not properly formatted.
Many other online references lack access-date and other basic information.
Some lists are of lesser relevance like "municipalities". These, if present, could be in collapsed state as to avoid taking up too much space.
Fossil and stratigraphy tables, albeit helpful should be in collapsed state as to bring the prose to forefront of the article.
Citations are needed in various places. Look up for "citation needed" inline templates.
In the economic geology section there is no mention of worl-class open pit mines nor is it clear if gold comes from modern place deposits or is mined from the basin strata.
I will do a quick check for image copyright once their numbers are reduced. A check on Earwig's Copyvio Detector gives a " Violation Unlikely" (24.8%
confidence) result.