Shades of Jurassic Park! Miniature dinosaur “exquisitely preserved in amber”

Guest “amateur paleontology” by David Middleton

NEWS 11 MARCH 2020
This miniature skull belonged to a 2-gram dinosaur

The 100-million-year-old animal might have been the smallest dinosaur.

Giuliana Viglione

A miniature creature exquisitely preserved in amber for almost 100 million years is probably the smallest dinosaur ever discovered.

The animal’s bird-like skull, described in Nature on 11 March1, is less than 2 centimetres long — suggesting that the creature was the size of the bee hummingbird (Mellisuga helenae), the smallest living bird. Its discovery could help scientists understand how such creatures evolved to be so small.

“It reveals to us a whole new lineage of birds,” says Jingmai O’Connor, a palaeontologist at the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, who co-led the study.


Further research on the fossil — for example, looking for biomolecules in its preserved soft tissue — will require advances in research techniques that don’t damage the specimen, O’Connor says.



A dino-bird in amber…

Beats two mosquitoes in an amber mine…

Tiny bird fossil might be the world’s smallest dinosaur
A tiny skull trapped in 99-million-year-old amber suggests that some of the earliest birds evolved to become miniature. The fossil illustrates how ancient amber can act as a window into the distant past.

Roger B. J. Benson

Dinosaurs were big, whereas birds — which evolved from dinosaurs — are small. This variation is of great importance, because body size affects lifespan, food requirements, sensory capabilities and many other fundamental aspects of biology. The smallest dinosaurs1 weighed hundreds of grams, but the smallest living bird, the bee hummingbird (Mellisuga helenae)2, weighs only 2 grams. How did this difference come about, and why? In a paper in Nature, Xing et al.3 describe the tiny, fossilized, bird-like skull of a previously unknown species, which they name Oculudentavis khaungraae. The discovery suggests that miniature body sizes in birds evolved earlier than previously recognized, and might provide insights into the evolutionary process of miniaturization.

Fossilization of bones in sediments such as clay, silt and sand can crush and destroy the remains of small animals, and can flatten and decay soft parts such as skin, scales and feathers. By contrast, preservation of small animals in Burmese amber (which formed from the resin flows of coniferous trees about 99 million years ago) helps to protect their soft parts. A wide range of invertebrates4 and small vertebrates, including lizards5 and birds6, have been found in Burmese amber. Specimens preserved in this material are rapidly emerging as an exceptional way to study tiny vertebrates from the age of dinosaurs5,6.

It is in Burmese amber that the single known fossil skull of Oculudentavis has been preserved (see Fig. 1a of the paper3). Oculudentavis means eye tooth bird, a name that Xing et al. chose because of two unusual features of the skull, each of which provides evidence about the likely lifestyle of this 99-million-year-old species.


The evolutionary relationships between Oculudentavis and other dinosaurs and birds are difficult to determine, but are central to clarifying the evolutionary implications of this discovery. Xing and colleagues’ analysis suggests two possibilities. Oculudentavis could belong to the most common group of birds of the Cretaceous period (about 145 million to 66 million years ago), the enantiornithines. Alternatively, it could be much more closely related to dinsosaurs, lying almost midway on the evolutionary tree between the Cretaceous birds and Archaeopteryx, the iconic winged dinosaur from the Jurassic.



The paper is pay-walled. Here’s the abstract:

Published: 11 March 2020
Hummingbird-sized dinosaur from the Cretaceous period of Myanmar
Lida Xing, Jingmai K. O’Connor, Lars Schmitz, Luis M. Chiappe, Ryan C. McKellar, Qiru Yi & Gang Li
Nature volume 579, pages 245–249(2020)


Skeletal inclusions in approximately 99-million-year-old amber from northern Myanmar provide unprecedented insights into the soft tissue and skeletal anatomy of minute fauna, which are not typically preserved in other depositional environments1,2,3. Among a diversity of vertebrates, seven specimens that preserve the skeletal remains of enantiornithine birds have previously been described1,4,5,6,7,8, all of which (including at least one seemingly mature specimen) are smaller than specimens recovered from lithic materials. Here we describe an exceptionally well-preserved and diminutive bird-like skull that documents a new species, which we name Oculudentavis khaungraae gen. et sp. nov. The find appears to represent the smallest known dinosaur of the Mesozoic era, rivalling the bee hummingbird (Mellisuga helenae)—the smallest living bird—in size. The O. khaungraae specimen preserves features that hint at miniaturization constraints, including a unique pattern of cranial fusion and an autapomorphic ocular morphology9 that resembles the eyes of lizards. The conically arranged scleral ossicles define a small pupil, indicative of diurnal activity. Miniaturization most commonly arises in isolated environments, and the diminutive size of Oculudentavis is therefore consistent with previous suggestions that this amber formed on an island within the Trans-Tethyan arc10. The size and morphology of this species suggest a previously unknown bauplan, and a previously undetected ecology. This discovery highlights the potential of amber deposits to reveal the lowest limits of vertebrate body size.


Cool schist! Unless… someone gets the bright idea to genetically engineer dinosaurs from “biomolecules in its preserved soft tissue”… 😉


Xing, L., O’Connor, J.K., Schmitz, L. et al. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature 579, 245–249 (2020).

Featured Image

Oculudentavis khaungraae is had a skull that was less than 2 centimetres long.Credit: Lida Xing (Nature)

72 thoughts on “Shades of Jurassic Park! Miniature dinosaur “exquisitely preserved in amber”

    • Yes. It’s good to break from insanity periodically and remember there are cool and amazing things in the world. Dinosaurs happen to be one of those very cool things. 🙂

        • A tiny flying bird-like dinosaur had to be warm blooded.

          It’s pretty much a toothed bird.

          As I recall, chickens still have the genes for teeth. They’re just turned off. SciAm has that story.

          • Scarce as hen’s teeth!

            Jack Horner still wants to make a dinochicken by turning back on the genes for teeth, a long, bony tail, three separate clawed fingers and maybe the raptorlike sickle toe, if that sequence hasn’t been lost. In most modern birds, but not all, two of the fingers are fused. The third (or “thumb”) works as a leading edge slat, the alula (“little wing”) for high angle of attack landings. Some non-avian dinosaurs had one, too.

            Triassic theropods still had five fingers, Early Jurassic four, but by the Middle Jurassic, they were down to three. Some Cretaceous theropods got down to one. T. rex had two and a stub not readily visible.

  1. Having a big mistake in the first sentence is distracting.
    Birds didn’t evolve from dinosaurs, they shared a common ancestor with dinosaurs.

    • Birds are dinosaurs … Theropods …. get Steve Brusattes book – The Rise and Fall of the Dinosaurs and read chapter 8 Dinosaurs take flight.
      From page 282 : The Liaoning fossils confirm where birds perch on the dinosaur family tree. Birds are a type of theropod; they are rooted in that group of ferocious meat eaters that most famously includes T.rex and Velociraaptor ………. The Liaoning fossils sealed the deal by verifying how many features are shared by birds and other theropods : not just feathers but also wishbones, three fingered hands that can fold against the body and hundreds of other aspects of the skeleton. There are no other groups of animals – living or extinct – that share these things with birds or theropods.
      Among the theropods, birds nest in an advanced group called the paravians.

    • Birds didn’t just evolve from dinosaurs. They are dinosaurs.

      Within the Superorder Dinosauria, they belong to Order Saurischia, Suborder Theropoda and a number of subgroups with shared derived traits on down to clade Coelurosaria, distinguished by feathers. Jurassic coelurosaurs were small predators, in contrast to their sister clade Carnosauria, which includes allosaurs. But in the Cretaceous, some coelurosaurs got big, to include the tyrannosaurs. Others however grew even smaller and evolved flight.

      Within Coelurosauria, birds nest among the maniraptors, ie the dinobirds, a diverse group whose sister clade is Ornithomimosauria. In order of increasing birdiness, Maniraptora includes insectivorous alvarezsaurs, giant herbivorous (rare among theropods) therizinosaurs, omnivorous oviraptorosaurs and Paraves, ie birds and their closest cousins, Deinonychosauria, eg “raptors” and troodontids, and Aves.

      The end Cretaceous extinction wiped most of the diverse Mesozoic birds, but happily some in the Ornithurae lineage survived to evolve into modern birds.

      • The Late Jurassic paravian Archaeopterix could fly, but not very well, as it lacked the keeled sternum evolved in the Cretaceous, which gives us chicken breast meat. Among the traits early bird Archie shared with its raptor kin was the characteristic sickle-clawed toe.

          • Today’s free range and caged dinosaurs do, although not all birds taste the same, just as dark and white chicken meat taste differently. Mesozoic dinos would have had an even wider range of taste, depending on what kind of muscle they had and what they ate.

          • “Tastes like chicken” seems to be an apomorphy of Archosauria. It applies to both extant branches, avians and crocodiles.

          • Some lepidosaurs, as well, ie snakes and lizards. Dunno about tuataras. Turtles now seem to be on the archosaur side of Reptilia, but don’t taste all that chickeny to me.

          • I would say chicken tastes like dinosaur 🙂
            I have a flying hook-bill dinosaur at home. One comment I could make is teeth are redundant, and I probably taste like human.

          • Try ostrich meat sometime. It looks like beef, and has a flavor all its own. I’ve only had it at Le Rendez-Vous Cafe, a French restaurant in San Bernardino, CA. It was exquisitely prepared, and became my go-to meal at that place. But then, I left the Inland Empire in 2008, so I don’t know if it’s still the same. Maybe I should have preserved my last leftovers in amber…

      • Birds didn’t just evolve from dinosaurs. They are dinosaurs.

        For years, whenever I have seen a chicken, I have thought “there goes a little dinosaur!”.

        • But for a little genetic Switch being off instead of on, feathers become scales (just look at the Emu feet compared to T-Rex)
          Another genetic Switch turned on and stubbed coxic bones become longer tails.
          Another Switch turns the hard edges of a Beak into teeth.

          Those genes are peasant today in birds just dormant

          • Yup, hen’s teeth are rare, but not impossible. You can turn the tooth genes on in chicken embryos. Some breeds of chicken grow feathers on their feet, just like their four-winged distant microraptor kin.

            The “parson’s nose” or pygostyle, fused caudal vertebrae from which grow tail feathers, evolved in the Cretaceous in the line leading to modern birds. Many Mesozoic birds lacked this feature, which gives better flight control.

            Even some ornithines retained teeth, especially sea and shore birds, but by the end of the Cretaceous water fowl had toothless beaks. So did little seed-eating birds, which diet and size helped them survive the harsh post-apocalyptic conditions.

        • “For years, whenever I have seen a chicken, I have thought “there goes a little dinosaur!”.”

          Ah, but why did it cross the road?

          Hear about the guy who ordered a chicken salad sandwich and an egg salad sandwich at the diner, at the same time, to see which came first?

          I feed the birds here, feeders on the upper deck. Getting to watch their behavior up close is always fascinating, lately the cardinals are starting to get frisky, I’m seeing males feeding females seeds at the feeder so mating behavior has begun. I always wonder, how much of their behaviors and such are unchanged from the days of their dinosaur ancestors?

  2. Cool schist! Unless… someone gets the bright idea to genetically engineer dinosaurs from “biomolecules in its preserved soft tissue”

    Perhaps it would be good to consider the methane to muscle ratio of such an engineered retro species relative to beef (in a warming world).

  3. I see a mini-Hockey Stick in that amber. Anyone else see it?
    They’re everywhere. They’ve been around for 97 (+/- 2) Mya.

    It grew up!!
    #97 lives

    • Mesozoic birds had far more standard theropod and maniraptoran traits than just teeth. Besides other identical anatomical features, we’ve recovered medullary bone from pregnant dinosaurs, present in modern female avians. Scientists have also recovered beta-keratin from dinosaurs, same as in birds.

      The conclusion that birds are dinosaurs is inescapable. The evidence is so overwhelming that even those ornithologists who in the ’70s and ’80s thought that birds and dinos descended from the same archosaur ancestors, with pterosaurs, but diverged from crocs, as shown by ankle structure and other features, today accept the fact that birds evolved from theropods. The Early Crretaceous Chinese fossils discovered from the ’90s have cinched the deal, with others from elsewhere.

  4. I had a year of vertebrate paleontology many eclipses ago. It is amazing to me how much keeps coming out. Textbook was Romer, heard him speak, knew his stuff, but asked him a question he couldn’t answer. Paleontologists are among the best of scientists because they have to know all the disciplines from archaeology to zoology. Not to ignore all that stratigraphy. More patience than climatologists.

    Great post!

  5. I once read a story about the T rex, and how it’s eyesight was so good, it could see its prey four miles away.

        • Maybe climb a tree.

          Bring a Barrett .50.

          T. rex and its closest kin weren’t just the top predators in their environments, but super predators (while not the largest theropods). Besides their awesome battery of senses and highest known bite force, they were relatively brainy for their time and probably hunted in packs or family groups. They were slower than some of their prey, so may have relied largely on ambush. And scavenging, thanks to their noses.

          Like giant vultures, they lost not just most or all of their head plumage as they grew, which they did rapidly, as do their avian kin, but body and tail feathers. Earlier small and medium tyrannosaurs sported fuzz, but by the Late Cretaceous, the big ones were mostly naked, with pebbly scales. Even T. rex chicks probably hatched with down, but progressively shed feathers as juveniles. Adults might have retained some display feathers.

  6. Neat posting, David. Often while working in the field of the Mesozoic Basin in Argentina, the Neuquen Basin, I would come across dinosaur fossils and get detoured from searching for copper or uranium. On an average day I would see 20 bones, and the best day around 2,000. If a possibly important example was discovered it was photographed, gps coordinates and notes collected, and when we finished in an area we would give the notes and photos to the areas designated paleontologist. No amber, of course, but lots of clear indications that herds of dinosaurs lived in the dense vegetation along river banks in a generally desert environment.

    • The Cretaceous environment in your AO continued to resemble the Jurassic of North America, so that giant sauropod herbivores and allosaur-related predators persisted there, while dying out on the other continent, to be replaced by new fangled ornithischian plant-eaters and tyrannosaurs. Toward the end of the period, sauropods reappeared in North America, presumably as immigrants from Asia or more likely South America, after a lapse of some 30 million years.

      Sauropods floated, so could have island hopped from south to north in the Western Hemisphere, when passage of the Caribbean Plate between the continents made the trip feasible.

      • It has been theorized that sauropods mated in water, since it is hard to see how the could have managed it otherwise.

        • Some might have been able to rear up on their hind legs. Their ancestors after all were bipedal.

          If so, quite a sight, allowing even those which couldn’t raise their heads far to feed on tall trees.

  7. Evolutionary, a bit bold since the missing link is yet to be found.

    It is extraordinary finding the bird in amber.

    • Which links do you think are missing? Feathered dinos evolving ever more avian characteristics are all links.

      The fossil record can’t preserve every species of an evolutionary transition, but in many cases plenty enough have been found to reach a conclusion. That’s true of birds. No other group shares so many derived traits with birds. The list is long, and increases as you go along the lineage leading to Aves.

      To mention but a few such traits: feathers, skeletal features too numerous to mention, breathing system via air sacs in hollow bones, reproductive biology (the aforementioned medullary bone), sleeping posture, brooding and nesting behavior (also cited above) and gizzard stones.

    • Just what link is it that is missing? Thanks to finds in (mostly) China we now have a remarkably good series of not-yet-birds, more-or-less-birds and very-nearly-birds, as well as a lot of weird mesozoic birds quite different from the modern neornithines.

      • A good missing link was discovered in Bavaria in 1861. Had its preservation been worse, so that its feathers weren’t visible, Archaeopteryx would have been considered a small dinosaur closely related to Compsognathus from the same Late Jurassic site (as indeed it is). A classic dinobird, Archie had flight feathers, but also a toothy snout, three clawed fingers and a long, bony tail.

        With the discovery of its sickle toe in an even better sample, some paleontolgists have argued for moving Archie out of Avialae into its sister raptor clade, even though it was apparently capable of under-powered flight.


        In the Cretaceous, “bird” would be a fungible concept, thanks to all those not missing links still being alive. Does it mean any feathered dino capable of flight, or at least active gliding? Then a lot of dinos which probably wouldn’t be considered birds today would be included, and other more closely related to modern birds would be out, creating paraphyletic clades.

        Today, with no archosaurs between crocs and birds, categories seem more distinct than they really are.

  8. It would be interesting if someone could compare this fossil’s DNA to those of modern hummingbirds.

    • It would be genetically closer to modern birds than is the average dinosaur, but it’s in a basal position among Avialae. It might even be an opposite bird, off the line to modern birds, but we’d need its shoulder to know that.

      Hummingbird-sized dinosaur from the Cretaceous period of Myanmar

      It independently evolved some features superficially similar to hummingbirds, such as small size, but they’re not closely related. Bird evolution has been a lot faster than that of their closest living relatives, the crocodilians. Birds also have the smallest genomes of all amniotes, ie mammals and reptiles, which latter clade includes birds.

  9. “This miniature skull belonged to a 2-gram dinosaur
    The 100-million-year-old animal might have been the smallest dinosaur.”

    So how do they even know it already hatched or was full grown?
    What if an egg broke and a poor little chick fell in that fluid?

    • The authors know it’s an adult from the proportions of the skull*, the high degree of fusion between many of the skull bones and the morphology of certain elements like the upper jaw.

      *The eye is not proportionately large for its size and the beak is not short.

  10. In my amber collection, there is a perfectly preserved, complete ant and another one is a tiny wasp. The tree that preserved these guys died out about 84 million years ago so they’re at least that old. I’ve collected amber samples from the rock hounds for over 50 years.

  11. What part do you find “just so”, as opposed to scientific fact, ie a valid observation of nature?

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