A flyer that could also be a climber, suggesting behavioral flexibility
Há 160 milhões de anos, uma criatura alada habitava os céus jurássicos com uma capacidade que nenhum pterossauro conhecido possuía: escalar árvores com polegares oponíveis. Descoberto na China em 2019 e estudado por pesquisadores da Universidade Federal do ABC, o Monkeydactyl desafia o que acreditávamos saber sobre a anatomia e o comportamento dos répteis voadores, lembrando-nos de que a vida antiga era mais inventiva do que nossa imaginação costuma alcançar.
- Um fóssil encontrado no nordeste da China em 2019 carregava uma anomalia anatômica perturbadora: polegares oponíveis em um pterossauro, traço que a ciência reservava quase exclusivamente aos mamíferos.
- A descoberta abalou décadas de consenso paleontológico, pois os pterossauros eram compreendidos como criaturas do ar, não como escaladores ágeis de copas de árvores.
- Pesquisadores da Universidade Federal do ABC, em colaboração com instituições de vários países, uniram esforços para interpretar o que os ossos do Monkeydactyl revelavam sobre comportamento e nicho ecológico.
- A análise aponta para um animal de dupla habilidade — voador e escalador — que ocupava um espaço ecológico único no mundo jurássico, sem equivalente conhecido entre seus contemporâneos.
- A descoberta abre novas perguntas sobre quantos outros pterossauros podem ter desenvolvido capacidades insuspeitadas, e sobre o quanto o registro fóssil ainda guarda de surpresas por revelar.
Em meados de 2019, paleontólogos que trabalhavam no nordeste da China desenterraram um fóssil capaz de reescrever o que sabemos sobre os répteis voadores do Jurássico. A criatura, batizada de Monkeydactyl, viveu há cerca de 160 milhões de anos — numa era em que os pterossauros dominavam os céus. O que a tornou extraordinária não foi o voo, mas o que suas mãos podiam fazer.
O Monkeydactyl possuía polegares oponíveis, uma característica anatômica que associamos quase exclusivamente aos mamíferos, especialmente aos primatas. Nenhum outro pterossauro conhecido apresentava essa estrutura. Isso significava que o animal era capaz de escalar árvores com a destreza e a firmeza de um macaco moderno — algo que a paleontologia jamais havia atribuído a esse grupo.
Os pterossauros já eram criaturas notáveis por si mesmos: os primeiros animais conhecidos capazes de voo ativo, anteriores às aves por milhões de anos. Mas sua anatomia era considerada voltada para o ar, não para a manipulação do ambiente. O Monkeydactyl desfez essa fronteira, sugerindo um animal que caçava ou forrageava tanto nas copas quanto em pleno voo.
Pesquisadores da Universidade Federal do ABC, junto a instituições de vários países, debruçaram-se sobre o fóssil e concluíram que a diversidade de comportamentos dos pterossauros era maior do que o registro fóssil havia indicado até então. A descoberta levanta questões sobre outros pterossauros e os papéis ecológicos que podem ter desempenhado — e lembra que o mundo antigo era mais estranho e variado do que costumamos imaginar.
In the middle of 2019, paleontologists working in northeastern China uncovered a fossil that would force a reconsideration of what flying reptiles could do. The creature, named Monkeydactyl, lived roughly 160 million years ago during the Jurassic period—a time when pterosaurs ruled the skies. What made this particular specimen remarkable enough to draw the attention of researchers from Brazil's Federal University of ABC and institutions across multiple countries was not simply that it could fly. It was what its hands could do.
Monkeydactyl possessed opposable thumbs. This anatomical feature—the ability to rotate the thumb inward to grasp objects against the fingers—is something we associate almost exclusively with mammals, particularly primates. It is not something pterosaurs were thought to have. The discovery suggested that this ancient reptile could do something no other known pterosaur could: climb trees with the dexterity and grip of a modern monkey.
Pterosaurs themselves were already remarkable creatures. They were the first animals known to science capable of powered flight, predating birds by millions of years. These were not dinosaurs, though they lived alongside them. They were reptiles, and they dominated the air during the Mesozoic era. But like most reptiles, they lacked the kinds of hands that could manipulate their environment with precision. Their wings were formed from elongated finger bones stretched with membrane. Their feet and remaining digits were built for perching and launching, not for the kind of gripping and climbing that requires an opposable thumb.
Monkeydactyl changed that picture. The fossil evidence showed a creature that could both soar through the air and move through the canopy with the kind of agility we see in tree-dwelling primates today. This was not a creature confined to one ecological niche. It was a flyer that could also be a climber, suggesting a behavioral flexibility and a range of hunting or foraging strategies that paleontologists had not previously attributed to pterosaurs.
The implications ripple outward. If Monkeydactyl had opposable thumbs and could climb, then the diversity of pterosaur anatomy and behavior was greater than the fossil record had previously suggested. It raises questions about what other pterosaurs might have been capable of, what ecological roles they might have filled, and how they interacted with their environment. A creature that could hunt in the trees and then launch itself into flight occupied a space in the Jurassic world that no other animal quite filled.
The discovery also underscores how much remains hidden in the fossil record, waiting to be found and interpreted. A single well-preserved skeleton from northeastern China, studied by an international team of researchers, has the power to reshape our understanding of an entire group of extinct animals. Monkeydactyl is not just a curiosity—it is evidence that the ancient world was stranger and more varied than we had imagined, and that there is still much to learn from the stones.
Notable Quotes
Pterosaurs were the first animals known to science capable of powered flight, predating birds by millions of years— Paleontological consensus cited by researchers
The Hearth Conversation Another angle on the story
Why does it matter that a pterosaur had opposable thumbs? Weren't they already flying—wasn't that enough?
It matters because it tells us these creatures weren't one-trick animals. A pterosaur that could only fly was limited to what it could do in the air. But if Monkeydactyl could grip and climb, it could hunt in trees, rest in branches, maybe even care for young in ways we never imagined.
So you're saying it was more like a bat than a bird?
Not quite. Bats are mammals—they have the basic mammalian hand plan. Monkeydactyl was a reptile that independently evolved something similar. That's the shock. It suggests convergent evolution, or it suggests pterosaurs were far more diverse than we thought.
How do scientists even know it could climb? It's just a fossil.
The bones tell the story. The thumb is positioned and shaped in a way that allows opposition—the same mechanical principle as in primates. Combined with the claw structure and the overall hand anatomy, you can infer function. It's not a guess; it's reading the skeleton.
What does this change about how we think of the Jurassic world?
It expands the possibilities. If Monkeydactyl filled a niche that combined flight with arboreal hunting, then the Jurassic ecosystem was more complex, more subdivided. Different pterosaurs might have had different lifestyles. We've been thinking of them as a monolithic group. This suggests they weren't.