Hummingbirds are small, colorful birds known for their ability to hover in midair and fly backwards. They are found only in the Americas and are some of the smallest birds in the world. Hummingbirds flap their wings up to 80 times per second, allowing them to fly like helicopters. They have long, slender bills adapted for reaching into flowers to drink nectar.
The fossil record of hummingbirds only goes back about 30 million years. The oldest known hummingbird fossil was found in Germany and dates to around 30 million years ago in the Oligocene epoch. This indicates that hummingbirds split from their closest living relatives, swifts and treeswifts, sometime between 40-50 million years ago. Since then, hummingbirds have diversified into over 300 different species found across North, Central, and South America.
Oldest hummingbird fossils
The oldest definitive hummingbird fossil was discovered in the Fur Formation in Denmark. This fossil, named Eurotrochilus inexpectatus, dates to around 30 million years ago in the Oligocene epoch. Key features of the fossil indicate it was an early predecessor to modern hummingbirds, including:
- Long, slender, decurved bill – similar to a modern hummingbird’s bill adapted for nectar feeding
- Wing bones structured for hovering flight
- Toes arranged in anisodactyl pattern like hummingbirds (3 toes forward, 1 back)
In addition to E. inexpectatus, a few other primitive hummingbird fossils from the Oligocene have been found in Europe. These include Parargornis messelensis from Messel, Germany and Argornis caucasicus from the Maykop Beds of the northern Caucasus. The existence of these early European hummingbirds suggests that hummingbirds originally evolved in Eurasia, then later migrated to the Americas.
Hummingbird fossils from North and South America
Once hummingbirds reached the Americas, many new species evolved and diversified. Some key fossils representing New World hummingbirds are:
- Jungornis – 23 million years old from Brazil – small size indicates an early hummingbird ancestor
- Precursornis – 10 million years old from Brazil – oldest New World fossil definitively identifiable as a hummingbird
- Lophornis brachylophus – 5 million years old from Florida – extinct hummingbird species
- Selasphorus sedeni – 3 million years old from Chili – resembles today’s Calliope hummingbird
These and other fossils trace hummingbird evolution in the Americas and the emergence of modern hummingbird diversity. As hummingbirds spread southward, they followed flowering plant diversification, evolving adaptations to feed from specialized flower shapes. There are now over 140 hummingbird fossils from the New World charting their evolutionary history.
Hummingbird evolutionary adaptations
Hummingbird fossils exhibit specialized features for hovering flight and feeding on nectar, representing some of their unique evolutionary adaptations:
- Winged skeleton – Hummingbird wing bones are fused and very short relative to body length, providing the stiffness needed to beat wings up to 80 times per second.
- Short, wide sternum – The breastbone has a wide surface for flight muscle attachments needed to hover and fly in all directions.
- Inverted central toe – Anisodactyly allows hummingbirds to grip flowers and branches.
- Long bill with tapered tip – Ideal for probing into flowers and accessing nectar.
- Enlarged brain processing centers – Expanded sensory and motor processing regions control complex flying and visual displays.
These adaptations enabled hummingbirds to fill an ecological niche as specialized nectar feeders and masterful aerialists. The evolution of these features is documented across the 30 million year hummingbird fossil record.
Key hummingbird fossil discoveries
Some major fossil discoveries have revealed key insights into hummingbird evolution:
| Fossil name | Age | Significance |
|---|---|---|
| Eurotrochilus inexpectatus | 30 million years old | Oldest definitive hummingbird, shows nectar-feeding adaptations |
| Precursornis | 10 million years old | Oldest New World hummingbird |
| Lophornis brachylophus | 5 million years old | Demonstrates hummingbird diversity in Miocene |
| Selasphorus sedeni | 3 million years old | Oldest Calliope-like hummingbird |
These and other important finds have allowed paleontologists to piece together the evolutionary history of hummingbirds since their split from swifts 50 million years ago. The fossils provide evidence of their adaptation for hovering flight, nectar-feeding, and dispersal across continents.
Conclusion
In summary, the oldest definitive hummingbird fossils come from Europe around 30 million years ago in the Oligocene period. These primitive hummingbirds had long slender bills and wing bones adapted for hovering flight. Over time, hummingbirds diversified into many new species as they dispersed across the Americas, following the radiation of flowering plants. They evolved specialized features like an inverted toe and enlarged sensory brain areas to excel as aerialist nectar feeders. While the fossil record is limited, key finds have revealed the major stages of hummingbird evolution over the past 50 million years since their divergence from swifts. Modern research and fossil discoveries continue to uncover new details about the origins and adaptations of these unique birds.
