A new order of insect found in Cretaceous amber

There are about 30 orders of insects (see here), usually ending with the letters “-ptera”. You should know some of these, including Lepidoptera, Coleoptera, Orthoptera, Hemiptera (“true bugs”), Diptera (FLIES!), Hymenoptera (ants, bees, and wasps), and as many of the others as your brain can hold. Rarely do we find a new one, as most of these are large, well-studied groups. But of course there are many extinct insects to be found, and the 1 million or so living species already described must be but a small fraction of all species still with us.

However, a new paper by Georger Poinar Jr. and Alex Brown in Cretaceous Research (reference below, access free), identifies a bizarre insect that doesn’t fit into any existing or extinct order, and thus has been placed in an order of its own. (See also the Oregon State University writeup, which is where first author Poinar works).

The insect, named Aesthiocarenus burmanicus, and assigned to the new order Aethiocarenodea, was found in amber excavated in Burma, and has been dated at about 99 million years ago, in the mid-Cretaceous.  Here’s a picture of the thing, and what is unusual is its “triangular head with bulging eyes,” described in the paper as an isoceles triangle with the hypotenuse being the front of the head.  This kind of head is absolutely unique in all known insects.

The creature is small (3-4 mm long) and wingless, but it’s a female, and we have no idea what the male looks like. But the degree of preservation in amber (remember, the bug got trapped in tree resin that then became amber) is remarkable.

The shape of the head, and narrow neck, lead the authors to speculate that this organism could move each eye through 180°, giving it really good vision. Notice the dorsoventral flattening:

Microsoft Word - ycres_3501_Revision unmarked Poinar-Brown_V2

(from paper): Holotype of Aethiocarenus burmanicus gen. et sp. nov. in Myanmar amber. A. Dorsal view of entire specimen. Scale bar = 1.5 mm. B. Dorsal view of head, neck and anterior portion of pronotum. Scale bar = 0.4 mm. C. Lateral view of entire specimen. Scale bar = 1.1 mm.

Because of its shape and winglessness, the authors suggest its lifestyle:

Based on the non-specialized mouthparts, A. burmanicus gen. et sp. nov. was probably omnivorous. The narrow, flattened body suggests it could have explored bark fissures and epiphytes on tree surfaces. Wings would have been a hindrance in such a habitat. The long slender polymerous antennae were probably used to explore the surroundings and the long, slender legs indicated that it could move quickly if threatened.

This figure shows two interesting features: a weird pattern of bristles on the thorax (arrows in vertical panel to the left, A), whose function is unknown, and some kind of secretory glands at the base of head shown in lower left panel (C). These glands apparently produced an exudate (globules indicated by arrows at bottom) when the insect found itself trapped in the resin. As the paper notes:

The dorsal neck glands presumably were used for defense. Evidence that these glands were secretory is the presence of two spherical bodies with irregular borders adjacent to the paired glands (Fig. 2C). These spherical bodies are considered to represent secretions released when the fossil entered the resin.

Microsoft Word - ycres_3501_Revision unmarked Poinar-Brown_V2

(from paper) Holotype of Aethiocarenus burmanicus gen. et sp. nov. in Myanmar amber. A. Dorsal view of base of pronotum, mesonotum and metanotum. Arrows show strange setal pattern on dorsum of mesonotum and metanotum. Scale bar = 0.2 mm. B. Lateral view of head showing antennal insertion and ocellus (arrow). Scale bar = 167 μm. C. Secretory glands (upper arrows) and secretion deposits (lower arrows) on neck. Scale bar = 68 μm.

This specimen is a female, as shown by the “gonopore” on the bottom of the abdomen (below). The authors note that it’s not clear whether a male, of which there are as yet no specimens, would have a head of the same shape, or might even have wings. (As we learned yesterday, sexual selection can sometimes cause big differences between the sexes in head shape).

screen-shot-2017-01-27-at-1-16-10-pm

F. Gonopore (arrow) on ventral sternite. (Female genitalia). Scale bar is 130 microns (0.13 mm)

Finally, is this related to any insects we know? The authors point out that the specimen has some features of one suborder of dermapterans (earwigs), but don’t share other features, so for now this order stands alone—with unknown genealogical affinities.

h/t: Dom

_____________

Poinar Jr, G. and A. E. Brown. 2016. An exotic insect Aethiocarenus burmanicus gen. et sp. nov. (Aethiocarenodea ord. nov., Aethiocarenidae fam. nov.) from mid-Cretaceous Myanmar amber. Cretaceous Research 72: 100-104

51 Comments

  1. Gamall
    Posted January 29, 2017 at 10:29 am | Permalink

    To the completely untrained eye, it looks a lot like a slightly comical ant. [source: my untrained eyes].

    • Mark Joseph
      Posted January 29, 2017 at 10:50 am | Permalink

      That was my first thought, too, although admittedly my eye is every bit as completely untrained as yours!

      • kieran
        Posted January 29, 2017 at 11:43 am | Permalink

        I thought it looked a little bit like a praying mantis with an ants body.

    • Posted January 30, 2017 at 12:32 pm | Permalink

      My untrained eyes were reminded of one of those animated insect movie characters – like from _Antz_, _A Bug’s Life_ or something.

  2. mordacious1
    Posted January 29, 2017 at 10:30 am | Permalink

    You’d think with such good eyes, she would have seen the tree sap.

    • Janet
      Posted January 29, 2017 at 10:42 am | Permalink

      ha ha

  3. Posted January 29, 2017 at 10:44 am | Permalink

    Am I the only person who thinks it is incredibly cool that we can tell a lot about its lifestyle from looking at a preserved — static! — specimen?

    • Mark Joseph
      Posted January 29, 2017 at 10:54 am | Permalink

      Shh. You’re scaring Ken (“there’s no such thing as historical science”) Ham!

      Of course, this fossil, and thousands of others like it, as well as all of geology, astronomy, and others refute his silly claim, but still, we have to be nice to the feebleminded.

      And, yes, it is incredibly cool!

    • Kiwi Dave
      Posted January 29, 2017 at 1:59 pm | Permalink

      Not the only person at all. To see a world in a grain of sand…

    • Gamall
      Posted January 29, 2017 at 4:45 pm | Permalink

      Meh. Cross it with frogs, make it giant, and built a theme park on a remote island, and *then* it’ll be incredibly cool.

      Right now it’s just *credibly* cool. 😎

    • Wunold
      Posted January 30, 2017 at 6:33 am | Permalink

      While reading, my awe about modern science’s abilities grew by the second.

  4. Tom
    Posted January 29, 2017 at 10:57 am | Permalink

    If it were not so tiny I would guess by the head it was on its way to becoming a Mantis mimic

  5. Mark Joseph
    Posted January 29, 2017 at 11:00 am | Permalink

    One comment (trivial) and one question (serious):

    I’m reading (and loving!) the science post!

    Question: how are fossils in amber dated? I wondered about this when there was another post here, the one about the feathered dinosaur tail in amber, also about 99 million years old, but never got around to asking. It’s way too old for carbon-14. Is the piece of amber itself in some sedimentary rock that can be radiometrically dated? Thanks in advance.

    • Mark Sturtevant
      Posted January 29, 2017 at 11:28 am | Permalink

      Dating amber is done by two methods that I know about. One is that the deposits are found above a rock layer with a known date and below a layer of another known date. So the amber containing layer is somewhere between the dates. The second way is to use ‘indicator fossils’. In this case this would be species trapped in the amber that have a known age. So other specimens in the same amber deposit should have the same age.

      • Mark Joseph
        Posted January 29, 2017 at 11:29 am | Permalink

        Excellent. Thank you!

      • Wunold
        Posted January 30, 2017 at 6:35 am | Permalink

        Also thanks from me, I wondered the same and found your answer in the comments. 🙂

        • Mike
          Posted January 31, 2017 at 8:12 am | Permalink

          Ditto

    • jaxkayaker
      Posted January 29, 2017 at 3:07 pm | Permalink

      It’s not clear from your question whether you realize that there are forms of radiometric dating other than carbon-14, some of which can date materials back to before the formation of the earth.

      https://en.wikipedia.org/wiki/Radiometric_dating#Modern_dating_methods

  6. Michael Fisher
    Posted January 29, 2017 at 11:10 am | Permalink

    What does “dorsoventral flattening” mean?

    As in: “The shape of the head, and narrow neck, lead the authors to speculate that this organism could move each eye through 180°, giving it really good vision. Notice the dorsoventral flattening:”

    • Mark Sturtevant
      Posted January 29, 2017 at 11:23 am | Permalink

      It looks like it could turn its head. Dorsoventral flattening means it looks squashed, as seen from the side. That appears to not be an artifact, so this insect was flat, and so perhaps could crawl under bark.

      • Gregory Kusnick
        Posted January 29, 2017 at 1:47 pm | Permalink

        Turning the head makes more sense than moving each eye. Aren’t insect eyes fixed to the cuticle?

        • loren russell
          Posted January 29, 2017 at 2:36 pm | Permalink

          Yes, it’s the head that’s very mobile , in this insect, providing a potential for panoptic vision. Eyes are fixed on the head capsule in all insects that I can think, including the stalk-eyed flies we saw yesterday.

    • Posted January 29, 2017 at 11:25 am | Permalink

      The dorsal aspect of an animal is the back and ventral is the belly. The specimen is flattened top to bottom rather than laterally (side-to- side).

  7. Mark Sturtevant
    Posted January 29, 2017 at 11:21 am | Permalink

    I have been following this interesting story. It looked to me like it had some affinity to Orthopteroid insects (several orders, including roaches, grasshoppers, etc.), and so its nice they found some similarity to the Dermaptera. It does look superficially like a Grylloblattid, but I certainly doubt it is one of those.

    One weird thing, seen from the side, is it has a petiole! That is the narrow, two-segmented waist where the abdomen joins the thorax. That is a feature that is typical of many hymenoptera, like ants, but it should not have affinity to that group since it has cerci (the little feelers at the end of the abdomen).

    Very, very strange.

    • loren russell
      Posted January 29, 2017 at 2:58 pm | Permalink

      Yes, almost certainly orthopteroid, and both dermaptera [earwigs] and grylloblattids [ice crawlers] are possible relatives.
      The complete lack of wings in this insect and relatively generalised anatomy of orthopteroids makes it hard to assign this to any known group. [The same can be said for the surviving icecrawlers and the related, very peculiar ‘rock crawlers’in South Africa — lack of wings makes their relationships enigmatic, though these latter groups have been linked to a fairly diverse fossil group of winged insects.]

      Another connection might be to the stick insects [Phasmatodea], which also have paired defensive glands on the forebody [in phasmatodea opening on pronotum rather than the head].

      The resemblance to an ant is interesting — primitive, stinging ants are known from the Burmese amber fauna — so it’s possible that this is an ant mimic [?Mullerian, perhaps, if the defensive glands are indicative.]. It could also be compared with living ant inquilines, which often assume the form of ants while manipulating the social pheromones of the ant society. [Note the reference to odd pubescence on the thorax– we see special tufts of setae to spread the pheromones in widely unrelated ant inquilines today.]

  8. Posted January 29, 2017 at 11:21 am | Permalink

    It reminds me a bit of the alien insects from the 1950’s Quatermass and the Pit.

    • loren russell
      Posted January 29, 2017 at 3:40 pm | Permalink

      FWIW, the Burmese amber has previously yielded another one-off insect order, the Alienoptera!

    • Posted January 29, 2017 at 4:25 pm | Permalink

      Yes!

  9. Lee Eberly
    Posted January 29, 2017 at 11:44 am | Permalink

    Would someone please explain “gen. et sp. nov.”

    Thanks

    • Posted January 29, 2017 at 12:09 pm | Permalink

      I guess, “genus and species (are) new”.

  10. Posted January 29, 2017 at 11:45 am | Permalink

    Minor point: the first author’s name is spelled Poinar not Poiner. Needs correction in both text and citation.

  11. Posted January 29, 2017 at 11:51 am | Permalink

    The abdominal cerci is reminiscent of an earwig.

  12. Christopher Bonds
    Posted January 29, 2017 at 12:29 pm | Permalink

    I wonder what caused it to go extinct? Or do we even know for sure that it is? I’m guessing loss of habitat, perhaps due to climate change?

    Very fascinating — a whole new order!

    • gravelinspector-Aidan
      Posted January 31, 2017 at 6:24 pm | Permalink

      Between the Cretaceous and now there have been the Deccan flood basalt province (think – a Tambora every couple of years. That’s the 1815 “year without a summer”) , the Chixulub impactor (even if it wasn’t the dinosaur killer, it was still a bad hair day for every species on the planet), faunal overturn (bye bye non-avian dinosaurs, hello bigger mammals), opening of the South Atlantic ; opening of the Indian Ocean, closing of Tethys (another ocean), opening of the Southern Ocean encircling Antarctica and allowing the establishment of permanent Antarctic glaciation, opening of the North Atlantic (including triggering the greatest dump of carbon into the atmosphere before the evolution of humans), raising of the Himalayas (lowering CO2 levels through the silicate-CO2 feedback, so triggering the expansion of the Antarctic ice cap and the establishment of the Greenland ice sheet) … Oh, I’m losing count. At least four Yellowstone major eruptions (2ft thick compressed ash deposits from Colorado to the ice sheet margin). Toba – allegedly almost wiped out humankind as it’s approximately coincident with the “Genetic Eve” population bottleneck.

      I wonder what caused it to go extinct? Or do we even know for sure that it is?

      To the first question, no. We have a point in time at which we know it existed, so it became extinct later ; without more specimens, no more can be sai. To the second question : I can’t think of any species that has continuity back to the Cretaceous. The old standbys don’t work : Lingula has existed as a genus since the Cambrian, but with a succession of distinct morphological species across time, and the coelacanth that exists today isn’t even in the same (morphological) genus as the Cretaceous coelacanths (Latimeria vs Mawsonia, Macropoma and others). You might just squeak it with Magnolia – plant fossils aren’t my strong point.

    • Christopher Bonds
      Posted February 1, 2017 at 2:06 pm | Permalink

      I guess one of the things I would like to know is why it appears to have left no evolutionary descendants today.

  13. Posted January 29, 2017 at 12:44 pm | Permalink

    George Poinar also has a series of articles with Ken Chambers on flowers caught in the Burmese amber.

  14. Gregory Kusnick
    Posted January 29, 2017 at 1:29 pm | Permalink

    access free

    Only to institutional subscribers, apparently; otherwise it’s $38.

    • gravelinspector-Aidan
      Posted January 31, 2017 at 6:41 pm | Permalink

      Try this link from Sci-Hub.

  15. ashdeville
    Posted January 29, 2017 at 3:33 pm | Permalink

    Quick! Tell Professor Quatermass!

    • Dominic
      Posted January 30, 2017 at 8:19 am | Permalink

      🙂

  16. Mark R.
    Posted January 29, 2017 at 4:14 pm | Permalink

    So it exuded something upon being stuck in the amber. Would this be similar to grasshoppers “spitting tobacco” when handled. Earwigs also have a nasty smell when handled (or maybe they always smell bad). What I’m getting at is the secretions must be a defensive mechanism. What a fascinating discovery.

  17. ThyroidPlanet
    Posted January 29, 2017 at 7:55 pm | Permalink

    Sub

  18. Dominic
    Posted January 30, 2017 at 8:18 am | Permalink

    Would those air bubbles tell us about the atmosphere at the time?! Or conceal microorganisms?

    • gravelinspector-Aidan
      Posted January 31, 2017 at 7:00 pm | Permalink

      Potentially, but it’s not simple. Once a bubble had formed, the air inside would become saturated with volatile compounds from the resin,, and they would change over time. Decomposition of the organism and any microbiota it contains or carries would probably release gases too. Oxidation of the resin would probably change the bulk composition.
      You can measure the gas composition simply enough (well … if you consider getting gas from sub-millimetre bubbles “simple” ; labs that do this for “fluid inclusion analysis” for hydrocarbon provenance studies do it routinely, but it costs a few hundred USD per sample. That does include finding the inclusions though.)
      How that measurement relates to the atmosphere at the time of bubble entrainment is not a simple question though.
      Claims have been made for the recovery of microorganisms from amber – IIRC Dominican amber from 40 Myr ago, but I’d have to go check that ; I think there have been older claims too – but the whole subject is extremely prone to questions of contamination. It’s not impossible, but it’s difficult (and disputed) work.
      The whole idea puts some serious demands on the putative population of microbes too, requiring extremely low levels of metabolic activity compatible with the permeability of the amber to waste products. Whether that’s enough to allow for necessary functions including repair of spontaneous damage to the genetic code, is an important point.

  19. Posted January 30, 2017 at 8:29 am | Permalink

    Cool! Thanks for posting this.

  20. Posted January 30, 2017 at 12:35 pm | Permalink

    Amber does it again! Seems we know a lot about ancient organisms because of this marvelous stuff.

  21. Wunold
    Posted January 31, 2017 at 2:47 pm | Permalink

    The insect, named Aesthiocarenus burmanicus, and assigned to the new order Aethiocarenodea

    Typo? (aeSthiocarenus)

  22. Wunold
    Posted January 31, 2017 at 3:04 pm | Permalink

    Embarrassingly, the German Wikipedia has no article about it, contrary to the English Wikipedia, as brief as it may be.


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