Fossil Spotlight

Fossil Spotlight: Maple Seed

Fossilized maple seed. Image from

Who: Maple Seed
Lagerstätte: Florissant Formation at Florissant Fossil Beds National Monument in Colorado
What: This is a maple seed preserved in shale at Florssiant Fossil Beds NM. The park is well known for its amazingly preserved insects and plants which are usually quite rare in the fossil record. It dates to the Eocene about 34 million years ago. Plant fossils like redwoods, hickory, elms, and rubber trees indicate that the area was once warm and humid; a far difference from its modern cold and drier climate. These plants were preserve in a lake which had occasional algal blooms. When plants or insects landed on the algal mat, they get entrapped and then fall to the lake’s bottom. The algae holds the leaves together and delicately buries them leaving a thin carbon film.


Fossil Spotlight

Fossil Spotlight: Pumiliornis, the Earliest Known Flower-Visiting Bird

Pumiliornis fossil; boxed area is the location of the pollen grains. Image from

Who: Pumiliornis tessellatus
Lagerstätte: Messel Pit in Germany
What: Pumiliornis is the oldest known flower-visiting bird in the fossil record at 47 million years old (Eocene Epoch). This is based on preserved pollen grains in its stomach! This strongly supports nectar-eating behavior further compounded by its beak which was long and likely flexible similar to hummingbirds. Fish and seeds have been found in birds stomach before, like the Jehol Biota in China, but pollen-finds are rarer and usually nectar-visiting behavior has to be inferred based on the fossil’s anatomy which can be difficult. Pumiliornis is not closely related to any known modern pollinators.

Close up of Pumiliornis stomach contents. Pollen grains circled. Image from

Mayr, Gerald, and Volker Wilde. “Eocene fossil is earliest evidence of flower-visiting by birds.” Biology Letters 10.5 (2014): 20140223.

O’Connor, Jingmai K., and Zhonghe Zhou. “The evolution of the modern avian digestive system: insights from paravian fossils from the Yanliao and Jehol biotas.” Palaeontology 63.1 (2020): 13-27.

Fossil Spotlight

Fossil Spotlight: Heliobatis radians

Who: Heliobatis radians
Lagerstätte: Green River Formation
What: Heliobatis is a freshwater stingray that lived in Wyoming during the Eocene period.  At the time, Wyoming used to be much warmer and wetter than it is today (think Louisiana) and was filled with freshwater lakes.  Stingrays are cartilaginous fishes related to sharks.  As such, its rare to have complete stingrays in the fossil record as they mostly lack hard parts; usually you would fine their teeth, scales or stings if you’re lucky.  However, the Green River Formation, where Heliobatis is found, is one of two places in the entire world with complete stingray fossils (and the only site with freshwater ones).  This is because the stingray’s lakes had a salty and anoxic bottom so when they died they fell to the bottom of the lake where they’re eventually burried and preserved almost to perfection.

File:Heliobatis radians, Lincoln County, Wyoming - Natural History Museum of Utah - DSC07176.JPG

“Freshwater stingrays of the Green River Formation of Wyoming (early Eocene), with the description of a new genus and species and an analysis of its phylogenetic relationships (Chondrichthyes, Myliobatiformes),” Carvalho et al. 2004
(Link is a download pdf provided by AMNH)