Eobelinae
Encyclopedia
Eobelinae are an extinct beetle
subfamily that throve in the late Mesozoic
. They belong to the belids or "primitive weevil
s" of the family
Belidae
. The Belidae today occur only from the Australia
-New Guinea
-New Zealand
region to Southeast Asia
, some Pacific islands, South
and Central America
and a few locations in Africa
. The Eobelidae were more widespread, occurring at least in Central Asia
, Spain
and Brazil
during the Late Jurassic
and Early Cretaceous
(about ).
("snout"), the latter being longer than the head and pronotum together. Like in other belids, their antenna
e were straight, not elbowed as in the true weevils (Curculionidae
); they insert near the rostrum's center. The "forehead" between the rostrum base and the eyes has a marked outward bulge. The tibiae
of the middle and hind legs have spurs at their tips.
Their larva
e are unknown. Presumably, like the living belids, they fed on the wood and fruits of diseased or dying plants or on deadwood, with healthy plants less important as food. Given that Araucariaceae
are the host plants of many of the older extant lineages of belids, it is quite likely that Eobelinae utilized these conifers too. Indeed, the Araucariaceae flourished at the same time as the Eobelidae, whereas most other known host plants of belids are angiosperms, a group of which the first primitive members (e.g. Archaefructus
) lived at the same time as the Eobelidae.
Eobelini, but the tribes of Belinae are attested in the Paleogene
; the radiation of the Belinae subfamilies thus probably took place later in the Cretaceous
. Thus treatment as a subfamily is most appropriate for the time being. It remains to be seen however if the Eobelidae as circumscribed here is monophyletic, or contains basal members of the extant belid subfamilies too.
Genera:
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
subfamily that throve in the late Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
. They belong to the belids or "primitive weevil
Weevil
A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...
s" of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Belidae
Belidae
Belidae is a family of weevils, called belids or primitive weevils because they have straight antennae, unlike the "true weevils" or Curculionidae which have elbowed antennae...
. The Belidae today occur only from the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
-New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
-New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
region to Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, some Pacific islands, South
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and a few locations in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. The Eobelidae were more widespread, occurring at least in Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
during the Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
and Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
(about ).
Description
Adult Eobelidae are recognizable by their elongated and flat body and long rostrumRostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
("snout"), the latter being longer than the head and pronotum together. Like in other belids, their antenna
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
e were straight, not elbowed as in the true weevils (Curculionidae
Curculionidae
Curculionidae is the family of the "true" weevils . It was formerly recognized in 1998 as the largest of any animal family, with over 40,000 species described worldwide at that time...
); they insert near the rostrum's center. The "forehead" between the rostrum base and the eyes has a marked outward bulge. The tibiae
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
of the middle and hind legs have spurs at their tips.
Their larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e are unknown. Presumably, like the living belids, they fed on the wood and fruits of diseased or dying plants or on deadwood, with healthy plants less important as food. Given that Araucariaceae
Araucariaceae
Araucariaceae, commonly referred to as araucarians, is a very ancient family of coniferous trees. It achieved its maximum diversity in the Jurassic and Cretaceous periods, when it was distributed almost worldwide...
are the host plants of many of the older extant lineages of belids, it is quite likely that Eobelinae utilized these conifers too. Indeed, the Araucariaceae flourished at the same time as the Eobelidae, whereas most other known host plants of belids are angiosperms, a group of which the first primitive members (e.g. Archaefructus
Archaefructus
Archaefructus is an extinct genus of herbaceous aquatic seed plants with 3 known species. Fossil material assigned to this genus originates from the Yixian Formation in northeastern China, originally dated as late Jurassic but now thought to be approximately 125 million years old, or early...
) lived at the same time as the Eobelidae.
Systematics
They are sometimes placed as a tribeTribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...
Eobelini, but the tribes of Belinae are attested in the Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
; the radiation of the Belinae subfamilies thus probably took place later in the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
. Thus treatment as a subfamily is most appropriate for the time being. It remains to be seen however if the Eobelidae as circumscribed here is monophyletic, or contains basal members of the extant belid subfamilies too.
Genera:
- Archaeorrhynchus Martynov, 1926 (Late Jurassic of Kazakhstan)
- Belonotaris Arnoldi, 1977 (Late Jurassic of Kazakhstan - Early Cretaceous of Russia)
- Davidibelus Zherikhin & Gratshev, 2004 (Early Cretaceous of Brazil)
- Eobelus Arnoldi, 1977 (Late Jurassic of Kazakhstan)
- Longidorsum Zhang, 1977 (Early Cretaceous of China)
- Microprobelus Ming, Dong & Chungkun, 2006 (Yixian Early Cretaceous of Lingyuan City, China)
- Montsecbelus Zherikhin & Gratshev, 1997 (Early Cretaceous of Spain)
- Probelopsis Arnoldi, 1977 (Late Jurassic of Kazakhstan)
- Probelus Arnoldi, 1977 (Late Jurassic of Karatau Range, Kazakhstan - Yixian Early Cretaceous of Hebei, China)