Roughly 105 million years ago, deep in what is now northern Spain, a small beetle became trapped in a droplet of sticky tree resin. As it struggled and thrashed in vain to free itself, the resin slowly encased its body, preserving it in a golden tomb that would endure for over a hundred million years. That beetle, recently discovered by scientists and named Darwinylus marcosi, has offered an extraordinary glimpse into a forgotten chapter of evolutionary history—a time when the Earth was still dominated by ancient plants and flowering plants had just begun their slow rise to ecological dominance.
The fossilized remains of Darwinylus marcosi were found preserved in amber, and this single specimen has provided researchers with not just a snapshot of an ancient beetle but also of a long-lost ecosystem and its complex web of interactions. The insect’s final moments were captured in remarkable detail. As it sank into the resin, grains of pollen that had clung to its body were released. More than a hundred of these tiny grains drifted away, but five stubbornly stayed attached, stuck to the beetle’s head and body. The presence of this pollen, alongside the beetle’s chewing mouthparts, painted a clear picture: this beetle had been actively feeding on pollen just before its untimely demise.
At first glance, that may not seem surprising. Today, beetles are among the many insects that feed on pollen and act as pollinators for flowering plants. But Darwinylus marcosi lived in an era before the world was covered in flowering plants. During the mid-Mesozoic, around the middle of the Cretaceous period, the Earth’s flora was dominated by gymnosperms—non-flowering plants like cycads, ginkgoes, bennettitaleans, and conifers. These plants produced seeds, but not flowers, and their reproductive strategies were very different from the flowering plants that would later cover the globe.
For decades, scientists have known that insects and gymnosperms had established pollination relationships long before angiosperms—flowering plants—emerged. However, the details of those ancient partnerships have remained murky. What the discovery of Darwinylus marcosi offered was direct evidence of a fourth, previously undocumented pollination strategy involving gymnosperms and insects. The beetle had chewing, jaw-like mouthparts and fed by consuming pollen directly, a feeding method distinct from the strategies seen in other ancient pollinators.
The find was significant enough to merit publication in the journal Current Biology on March 2, 2017. Conrad Labandeira, a paleobiologist at the Smithsonian’s National Museum of Natural History, explained that the fossil provides “the first, direct evidence of a fourth major gymnosperm-insect pollination mode during this time.” The discovery has helped clarify the diversity of ways insects interacted with ancient gymnosperms. While today most people think of bees and butterflies sipping nectar from flowers, insect pollination in the age before flowers was a very different affair.
Prior to the rise of flowering plants, several groups of insects had already established themselves as pollinators of gymnosperms. Fossil records from between 165 million and 105 million years ago show various insects—scorpionflies, lacewings, flies, moths, and thrips—feeding on and transporting gymnosperm pollen. Each group evolved its own specialized mouthparts and feeding methods suited to extracting rewards from gymnosperm reproductive structures.
Scorpionflies and lacewings had long, straw-like proboscises that they used to sip on pollination drops, sweet liquids exuded by gymnosperms from deep within funnel-like ovule structures. These drops were the gymnosperm equivalent of nectar, rich in sugars and other nutrients. Some flies evolved sponge-like mouthparts that allowed them to lap up the same pollination drops. Meanwhile, thrips developed punch-and-suck mouthcones, which they used to puncture pollen grains and extract their nutritious contents. These three distinct pollination modes—siphoning, sponging, and punching—were already well documented in the fossil record, with pollen grains found attached to the mouthparts, heads, and bodies of these insects, offering clear evidence of their roles as pollinators.
Darwinylus marcosi introduced a fourth method: chewing. Rather than sipping pollination drops or puncturing pollen grains, this beetle had evolved jaw-like mandibles designed for biting and grinding. This chewing mode of pollen consumption, preserved in amber for eons, demonstrated an entirely new type of insect-plant interaction in the mid-Mesozoic. According to Labandeira, the discovery fills an important gap in our understanding of how insect pollination diversified long before flowers became the primary attractors of pollinators.
Understanding the pollination dynamics of this time period is crucial because it sheds light on a major evolutionary transition. Between about 125 and 90 million years ago, a massive ecological turnover took place. Flowering plants, which had previously been rare and confined to specific niches, began to proliferate and outcompete gymnosperms across the world. This event, known as the Aptian-Albian Gap, marked a time when many gymnosperm species and their specialized insect pollinators went extinct, their tightly co-evolved relationships leaving them vulnerable to sudden changes in plant diversity and climate.
Some insects were able to make the leap from gymnosperms to angiosperms, adapting their pollination behaviors and mouthparts to the new types of plants and their reproductive strategies. Others were not so lucky. Insects that had evolved extremely specialized relationships with gymnosperms often found themselves stranded as their host plants disappeared, and many became extinct during this period of transition.
The few gymnosperm-pollinating insects that survived the extinction event saw a sharp decline in their diversity. Today, most gymnosperms, such as conifers and ginkgoes, rely primarily on wind for pollination. Only a few, like cycads and the unusual gnetaleans, still depend on insect pollinators.
Labandeira points out that Darwinylus marcosi represents a success story. Modern relatives of this beetle, part of a group known as false blister beetles, have fully transitioned to pollinating flowering plants. They no longer rely on gymnosperms and have become integrated into the complex and dynamic ecosystems dominated by angiosperms. This transition highlights an important evolutionary lesson: flexibility and generalist behavior often offer a better chance of survival in times of major environmental change.
The beetle’s chewing mouthparts were perfectly suited to pollen-feeding, whether the pollen came from gymnosperms or angiosperms. While the reproductive structures of gymnosperms and angiosperms are vastly different, the nutritional rewards they offer to pollinators—pollen and sweet fluids—are remarkably similar. As Labandeira explains, the protoplasts of gymnosperm pollen are virtually identical to those of angiosperms. Likewise, gymnosperm pollination drops and angiosperm nectar, though produced by different plant tissues, share similar compositions and nutritional content. This similarity made the transition between plant types easier for insects like Darwinylus marcosi.
Pollinators that had already developed feeding strategies allowing them to exploit a wide variety of gymnosperm species were better prepared to take advantage of the rising diversity of flowering plants. They could adapt their feeding and pollination behaviors without requiring major changes to their mouthparts or digestive systems. This versatility proved critical for survival.
However, the story of ancient pollinators also carries a cautionary message for the present. Labandeira notes that the tight co-dependence between ancient gymnosperms and their insect pollinators left them vulnerable to extinction. Today, similar threats exist for modern pollinators and flowering plants. Habitat loss, climate change, and the decline of pollinator species, such as bees and butterflies, echo the challenges faced by ancient ecosystems during the rise of angiosperms.
Understanding these deep evolutionary histories may offer insights into how current ecosystems might respond to ongoing environmental changes. The fossil record preserved in amber offers not just snapshots of ancient life but also lessons that are increasingly relevant today.
The discovery of Darwinylus marcosi and its role as an ancient pollinator underscores the complexity and longevity of insect-plant relationships. Long before the bright colors and intoxicating scents of modern flowers filled the world, insects were already hard at work transporting pollen and facilitating plant reproduction. The evolutionary success of flowering plants may owe much to the earlier, experimental partnerships forged between gymnosperms and their insect allies.
While the beetle’s final struggle in sticky resin marked the end of its life, the preservation of its tiny body has opened a window into a world few imagined. Thanks to discoveries like this one, scientists are piecing together the ancient roots of one of nature’s most important partnerships—between plants and the pollinators they depend upon.