What can we learn from a dinosaur feather preserved in amber? Let’s go behind the scenes of the Museum’s collection of amber fossils to find out!
A newly discovered 99-million-year-old fossil suggests that as soon as ancient insects began forming colonies, their nests became targets for parasitic beetles. The study, conducted by researchers at the Museum, Columbia University, and Kyushu University, was recently published in the journal Nature Communications.
This spider was trapped in tree resin about 20 million years ago. Over time, the resin fossilized to amber, preserving the animal inside. Specimens like this are helpful given that spiders don’t fossilize well in sediment. They offer researchers good information about the group’s more recent history. Learn more about the Museum’s amber collection.
Fossils in Amber Show Social Behavior in Ancient Insects
It's a ferocious Fossil Friday! Fighting ants, giant soldier termites, and foraging worker ants recently discovered in 100-million-year-old amber provide direct evidence for advanced social behavior in ancient ants and termites—two groups that are immensely successful because of their ability to organize in hierarchies.
The new work, led by scientists at the American Museum of Natural History and the University of Kansas, and published today in two papers in the journal Current Biology, proves that advanced sociality in ants and termites was present tens of millions of years earlier than indicated by the previous fossil record.
“Ecologically, advanced sociality is one of the most important adaptive features for animals,” said co-author Dave Grimaldi, a curator in the Museum’s Division of Invertebrate Zoology. “All ants and termites are social, and they are ubiquitous across terrestrial landscapes, with thousands of described species and probably even more that we haven’t yet found.”
Advanced sociality, or eusociality, a hallmark of which is reproductive specialization into worker and queen castes, is essentially a phenomenon of the phylum of invertebrates known as arthropods. Queens and reproductive males take the roles as the sole reproducers while the soldiers and workers defend and care for the colony.
The trait is thought to have appeared first in termites in the Late Jurassic, about 150–160 million years ago, but the earliest termites that could definitively be tied to a caste system dated from the Miocene, a mere 20 to 17 million years ago.
A number of spectacular pieces of amber recently recovered from Myanmar provided a clear answer: Eusociality was going strong in both groups during the Cretaceous, between 65 and 145 million years ago.
Insects evolved at least 420 million years ago, and over time became tremendously diverse and ecologically important. Amber, the fossilized resin from ancient trees, preserves whatever may have become trapped in it with microscopic clarity and vivid detail. Arthropods—including insects and arachnids—make up the majority of amber fossils, although plants and other invertebrates are also found. From this fossil record, scientists can trace evolutionary change over millions of years in exceptional detail.
The Museum's collection now holds tens of thousands of amber fossils from around the world, principally from the Early Cretaceous about 130 million years ago to the Miocene about 20 million years ago. The specimen pictured here is an extinct termite, Mastotermes electrodominicus, in Dominican amber, 1 1/3 inches (4.4 cm) long.
Ph.D. Profile: Phil Barden
Growing up in the Southwest, Phil Barden was always intrigued by animals, spending his free time “doing kid stuff,” like catching snakes and lizards. But in high school, when he mentioned his interest in nature to a guidance counselor, the man discouraged him. “Naturalists,” he said, “don’t exist anymore.” They were from “olden times,” an extinct species.
Despite this pessimistic counsel, Barden remained determined to find a way to study nature. In college at Arizona State University, he worked in a biology lab where the researchers studied eusociality, a trait of some animal groups, including insects like bees and ants, wherein most individuals forego reproduction for the benefit of the greater community.
During his four years at the Museum’s Richard Gilder Graduate School, Barden focused on study of ancient ant species. The early evolution of ants is poorly understood, and Barden and his advisor, David Grimaldi, wanted to find out more. Were early ants social or solitary animals, for instance? And from what lineage of ancient ants did the vast array of modern ant groups evolve?
In spring or summer, you can look down almost any street and see flowers blooming, on plants from dandelions to cherry trees. Flowering plants, or angiosperms, are some of the most successful and diverse forms of life on Earth. Researchers have long attributed that success, in part, to the alliances these plants have with insects that help to fertilize them by carrying pollen from one plant to another while they sip a meal of nectar.
It’s a win-win relationship, but new research from the American Museum of Natural History and partner institutions shows that anther category of plants known as gymnosperms—the group to which modern conifers belong—also benefitted from pollination by ancient insects.
The evidence comes from a fly specimen trapped in amber during the Cretaceous Period. Researchers had previously suspected these flies, which belong to the Zhangsolvidae family, were pollinators. That’s because of their distinctive mouthparts, says David Grimaldi, a curator in the Division of Invertebrate Zoology at the Museum and coauthor on the paper, which was published in the journal Current Biology.
“These flies had specialized features like a long proboscis that was adapted to probing plants for nectar,” says Dr. Grimaldi.
What kind of plant, though, was a mystery that this research solves.
NEW RESEARCH: Flies fossilized in amber provided researchers with new insight to their feeding habits.
Museum scientists have uncovered the fossil of a 52-million-year old beetle that likely was able to live alongside ants—preying on their eggs and usurping resources from the comfort of their nest.
The Eocene fossil, named Protoclaviger trichodens, was encased in a piece of amber from India and is the oldest-known example of this kind of social parasitism, or “myrmecophily.” Published today in the journal Current Biology, the research also shows that the diversification of these stealth beetles, which infiltrate ant nests around the world, correlates with the ecological rise of modern ants.
This spider was trapped in tree resin about 20 million years ago. Over time, the resin fossilized to amber, preserving the animal inside. Specimens like this are helpful given that spiders don’t fossilize well in sediment. They offer researchers good information about the group’s more recent history. The oldest known amber specimen is from around 130 million years ago. This specimen was collected in the Dominican Republic.
Learn more in our exhibition, Spiders Alive! open now.
Recently, a fourth-year student at the Museum’s Richard Gilder Graduate School, Phillip Barden, and Curator and Professor David Grimaldi, his graduate advisor, discerned nine “new” species of extinct ants preserved in Burmese amber (which, by the way, is fossilized tree resin).
Two of these species exhibit tusk-like mandibles, and appear to have been quite ferocious, possibly impaling prey with their uniquely expanded mouthparts.
Read more on the Museum's blog about how CT scans and light microscopy in the Museum’s imaging laboratory are uncovering information about these species.
This spider was trapped in tree resin about 20 million years ago. Over, time the resin fossilized into amber, preserving the animal inside.
© AMNH\D. Grimaldi
Preserved for 230 million years in droplets of amber just millimeters long, two newly named species of mites and a fly have set a record. They are the oldest arthropods – invertebrate animals that include insects, arachnids, and crustaceans – ever found in amber.
Researchers screened 70,000 amber droplets, resulting in the three arthropod inclusions. Read the full story: http://bit.ly/NA6nRN
Image: Photomicrographs of the two new species of ancient gall mites, taken at 1000x magnification. The gall mites were named (top) Triasacarus fedelei and (bottom) Ampezzoa triassica. (University of Göttingen/A. Schmidt)
This image shows how amber is set up to be photographed. It is placed on a plexi surface with light coming through from underneath. Shot by Denis
A few amber-related items from the Museum's collections, photographed by Craig