Mesophyletidae is an extinct family of

weevil Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small – less than in length – and herbivorous. Approximately 97,000 species of weevils are known. They belong to several fa ...

s known from a number of genera preserved in

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

amber Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia ...

. The family was first described as a subfamily in the

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

family Caridae, and subsequently raised to family status in 2018.

Distribution and paleoecology

The family is known exclusively from fossils preserved in

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. Th ...

, and combined with the Nemonychidae genera, the Burmese amber fauna is considered one of the richest weevil faunas of the Mesozoic, rivaling Kazakhstan's late Jurassic site at Karatau. The Burmese amber fossils preserve more detail than the compression fossils from Karatau. The amber paleoforest was tropical in temperature, and situated along the tidal boundary of a coastal estuary. The resin from which the amber originated is most likely araucarian, based on both inclusions of wood fragments and spectroscopic analysis. Based on the elongated

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

, antennae, and ovipositor structures; species in mesophyletidae were likely specialized herbivores which predated seeds and plant ovules in manners similar to that of the living Anthonomini, Curculionini, and related curculionid tribes. The legs are modified with elongated tarsi sporting large claws and

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

with strengthening ridges and a flattened or flared profile. These adaptations indicate an

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

life of climbing on smooth or flimsy plant organs such as leaves and fruits. Additionally the

elytra An elytron (; ; : elytra, ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometime ...

did not lock along the tips, and are loose to the

pygidium The pygidium (: pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is compos ...

which would allow for quick transition to flight, something the group was likely proficient at. They have enlarged eyes composed of coarse facets protruding on their heads, a feature seen in many weevil groups that spend their lives in dark canopies or in leaf litter.

History and classification

'' Mesophyletis'' was the first genus of the group to be described, with its type description being published in 2006. The genus was placed into the family " Eccoptarthridae", an older name sometimes used for Caridae, as one of the genera in the subfamily Mesophyletinae by George Poinar Jr. However, in the 2006 paper, no type genus was specified in the subfamily description and a subsequent paper in 2008 specified ''Mesophyletis'' as the type genus. The subfamily Aepyceratinae was proposed in 2017 as a part of the family Nemonychidae based on perceived similarities between '' Aepyceratus hyperochus'' and the nemonychids. The 2018 monograph on Burmese amber weevils expanded the group notably, and raised it to a full family, with two defined subfamilies, Aepyceratinae and Mesophyletinae. An additional five genera were described as part of Aepyceratinae, based on the structuring of the antennae, though the 2018 authors note that there are no other indications that the grouping is monophyletic.

Subfamilies and genera

Rhynchitomimus chalybeus holotype Fig1 B

up'' Nugatorhinus albomaculatus'' holotype *Aepyceratinae Poinar, Brown, & Legalov, 2017 **'' Acalyptopygus'' Clarke & Oberprieler, 2018 **'' Aepyceratus'' Poinar, Brown, & Legalov, 2017 **'' Burmophyletis'' Clarke & Oberprieler, 2019 (syn "''Platychirus''" Clarke & Oberprieler, 2018) **'' Calyptocis'' Clarke & Oberprieler, 2018 **'' Nugatorhinus'' Clarke & Oberprieler, 2018 **'' Rhynchitomimus'' Clarke & Oberprieler, 2018 *Mesophyletinae Poinar, 2008 (syn: Anchineini Poinar & Legalov, 2015; Burmocorynini Legalov, 2018; Mekorhamphini Poinar, Brown & Legalov, 2016) **'' Anchineus'' Poinar & Brown, 2009 **'' Aphelonyssus'' Clarke & Oberprieler, 2018 **'' Bowangius'' Clarke & Oberprieler, 2018 **'' Burmocorynus'' Legalov, 2018 **'' Burmorhinus'' Legalov, 2017 **'' Cetionyx'' Clarke & Oberprieler, 2018 **'' Compsopsarus'' Clarke & Oberprieler, 2018 **'' Cyrtocis'' Clarke & Oberprieler, 2018 **'' Debbia'' Clarke & Oberprieler, 2018 **'' Echogomphus'' Clarke & Oberprieler, 2018 **'' Electrocis'' Clarke & Oberprieler, 2018 **'' Euryepomus'' Clarke & Oberprieler, 2018 **'' Gnomus'' Clarke & Oberprieler, 2018 **'' Habropezus'' Poinar, Brown, & Legalov, 2016 **'' Hukawngius'' Clarke & Oberprieler, 2018 **'' Leptopezus'' Clarke & Oberprieler, 2018 **'' Louwiocis'' Clarke & Oberprieler, 2018 **'' Mekorhamphus'' Poinar, Brown, & Legalov, 2016 **'' Mesophyletis'' Poinar, 2006 **'' Myanmarus'' Clarke & Oberprieler, 2018 **'' Ocriocis'' Clarke & Oberprieler, 2018 **'' Opeatorhynchus'' Clarke & Oberprieler, 2018 **'' Periosocerus'' Clarke & Oberprieler, 2018 **'' Petalotarsus'' Clarke & Oberprieler, 2018 **'' Rhadinomycter'' Clarke & Oberprieler, 2018 **'' Zimmiorhinus'' Clarke & Oberprieler, 2019 (syn: ''"Elwoodius"'' Clarke & Oberprieler, 2018)

References

{{Taxonbar, from=Q96392711 Burmese amber Weevils Prehistoric insect families