Late Lutetian Thermal Maximum

The Late Lutetian Thermal Maximum (LLTM), also known as the C19r Event, was a hyperthermal event that occurred during the Lutetian epoch. == Timing == The LLTM occurred from around 41.535-41.505 million years ago, amidst a broader cooling trend known as the Middle-Late Eocene Cooling (MLEC), and lasted for around 30,000 years.

Source: Wikipedia — Late Lutetian Thermal Maximum (CC BY-SA 4.0)