Robuta

https://www.usgs.gov/publications/yorktown-formation-improved-stratigraphy-chronology-and-paleoclimate-interpretations The Yorktown Formation: Improved stratigraphy, chronology and paleoclimate interpretations from the... The Yorktown Formation records paleoclimate conditions along the mid-Atlantic Coastal Plain during the mid-Piacenzian Warm Period (3.264 to 3.025 Ma), a... yorktown formationimprovedstratigraphychronologypaleoclimate