Bucerotiformes

## About

bucerotiformes is the order which includes hornbills, scimitarbills and hoopoes. Previously, these species were classed as members of coraciiformes. bucerotiformes is comprised of six families which can be split further into twenty-two genera and seventy-seven species. Members of this order are most commonly characterised by their large or strong bills. bucerotiformes first appeared in the fossil record during the Eocene epoch (around 56-33.9 Mya) in Asia however, today they also occur additionally throughout sub-Saharan Africa, Europe and Melanesia.

## upupi

upupi is a bucerotiform suborder which includes both extinct and extant hoopoe and hoopoe-like bucerotiformes.

### Messilirrisoridae

Messilirrisoridae is the oldest known family belonging to the order bucerotiformes and is now completely extinct. The family is only known to have been comprised of one genus, being messilirrisore, which was comprised three species; ***(M. halcyrostris)***, ***(M. grandis)*** and ***(M. parvus)***. They were very early representatives of the hoopoes and wood hoopoes of the modern families; Upipidae and phoeniculidae respectively. Messilirrisorids first appeared in the fossil record during the Middle Eocene period of around 49-37 mya and occurred in Europe.

### Laurillardiidae

Laurillardiidae is an enigmatic and completely extinct bucerotiform family which was also comprised of just one genus categorising three species being; ***(L. longirostris)***, ***(L. munieri)*** and ***(L. smoleni)***. The latter two species are known from a site in Poland and date back to the Oligocene (33.7-23.7 mya). The species are the only remnance of a 25 million year gap in the bucerotiform fossil record between messilirrisoridae and laurillardiidae and the two families are thought to be very closely related. Laurillardiids coexisted which passerine birds for at least 10 million years, challenging the hypothesis that passerine birds eliminated bucerotiform birds in much of Europe on arrival.

## Extant Families

### Phoeniculidae

Phoeniculidae is comprised of five species of wood hoopoe as well as three species of scimitarbill. They are split into two genera; phoeniculus and rhinopomatus respectively and neither group are considered to be 'true-hoopoes'. Phoeniculus is the closest genera to true-hoopoes morphologically speaking, as the two groups share features like curved bills, similarly rounded wings and stapes (a middle-ear bone). Fossil evidence suggests that the two genera diverged from one another around 10 mya and so some taxonomists and systematists treat the two genera as different subfamilies of phoeniculidae or different families from one another as a whole.

### Upupidae

Upupidae is the family of true-hoopoes and is comprised of just three species belonging to one genus however, previously four other species were included in the genus, including the northern bald ibis ***(Geronticus eremita)***. These species have now been reclassed into more accurate orders and families, due to the fact they were only morphologically similar to hoopoes rather than being genetically similar. The true-hoopoe species themselves were once considered one species however, they have now been split into three species; the African hoopoe ***(Upupa africana)***, the Eurasian hoopoe ***(Upupa epops)*** and the Madagascar hoopoe ***(Upupa marginata)***. A fourth true-hoopoe was also considered a separate species; the St Helena hoopoe ***(Upupa antaios)*** however, it had gone extinct in the 16th century due to invasive species. Additionally, the entire family was also once considered part of Coraciiformes. The fossil record of upupidae is very incomplete, with the first members appearing in the fossil record in the Quaternary (2.58-0 mya).

## Buceroti

Buceroti is a suborder of bucerotiformes which includes the hornbills and ground hornbills.

### Bucorvidae

Bucorvidae is comprised of two extant ground hornbills which belong to the genus bucorvus, the two species being the southern ground-hornbill ***(Bucorvus leadbeateri)*** and the Abyssinian ground-hornbill ***(Bucorvus abyssinicus)***. Bucorvus was introduced originally as a subgenus by René Lesson (1784-1849) in 1830 however, it was later found that it was rather a sister group to bucerotidae. The extinct fossil species; ***(Barcovus brailloni)*** was described from Morocco, suggesting that the genus was either more widespread or occurred differently before the Quaternary glaciations.

### bucerotidae

bucerotidae is the largest bucerotiform family, being comprised of fourteen genera and fifty-four species occurring across Africa, Asia and Melanesia. bucerotids are thought to have convergently evolved from neurotropical new world toucans to fill the same ecological niche. bucerotids are considered to be different from bucorvids, as the family likely evolved in Asia, whereas bucorvids likely represent a more disjointed early African lineage of hornbills. bucerotids first appeared in the early Miocene. Hornbills are incredibly varied in morphology however, they all share the presence of a casque and a curved bill. They all also share characteristics of nest-sealing and frugivory, aside from a few omnivorous and carnivorous species.

## Sources

* bucerotiformes | Wikipedia - https://en.wikipedia.org/wiki/bucerotiformes
* Messelirrisor | Wikipedia - https://en.wikipedia.org/wiki/Messelirrisor
* Wood Hoopoe | Wikipedia - https://en.wikipedia.org/wiki/Wood\_hoopoe
* Hoopoe | Wikipedia - https://en.wikipedia.org/wiki/Hoopoe
* Ground Hornbill | Wikipedia - https://en.wikipedia.org/wiki/Ground\_hornbill
* Hornbill & Relatives | Encyclopedia of Life - https://eol.org/pages/8017
* Skeletons from the early Oligocene of Poland fill a significant temporal gap in the fossil record of upupiform birds (hoopoes and allies) | Bird Forum - https://www.birdforum.net/threads/laurillardia-smoleni-sp-nov.372925/
* The origin and diversification of Hornbills (bucerotidae) | ORA, University of Oxford - https://ora.ox.ac.uk/objects/uuid:73e7eba9-fb13-4877-b735-bed38e0c8ffb