The Jamaican ibis, Jamaican flightless ibis or clubbed-wing ibis (''Xenicibis xympithecus'') is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

bird species of the ibis subfamily uniquely characterized by its club-like wings. It is the only species in the genus ''Xenicibis'', and one of only two

flightless Flightless birds are birds that cannot fly, as they have, through evolution, lost the ability to. There are over 60 extant species, including the well-known ratites ( ostriches, emus, cassowaries, rheas, and kiwis) and penguins. The smal ...

ibis genera, the other being the genus '' Apteribis'' which was endemic to

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

's islands of

Maui Nui Maui Nui is a modern Geology, geologists' name given to a prehistoric Hawaii, Hawaiian island and the corresponding modern Biogeography, biogeographic region. Maui Nui is composed of four modern islands: Maui, Molokai, Molokaʻi, Lanai, Lānaʻi, ...

Description

The species was first described in 1977 based on postcranial bone elements excavated in a cave deposit at Long Mile Cave,

Jamaica Jamaica is an island country in the Caribbean Sea and the West Indies. At , it is the third-largest island—after Cuba and Hispaniola—of the Greater Antilles and the Caribbean. Jamaica lies about south of Cuba, west of Hispaniola (the is ...

, by H. E. Anthony in 1919–20.Suárez, William (2001
"Deletion of the flightless ibis ''Xenicibis'' from the fossil record of Cuba"
. ''Caribbean Journal of Science'' 37 (1–2): 109–110 At the time, it was presumed to be flightless based on the incomplete

coracoid A coracoid is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is present as part of the scapula, but this is n ...

; its flightlessness was confirmed after a

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

of the same species was found in the Swansea Cave, Jamaica. New fossil finds from two locations, including the Red Hills Fissure, show that the bird has a unique modification of the

carpometacarpus The carpometacarpus is a bone found in the hands of birds. It results from the fusion of the carpal and metacarpal bone, and is essentially a single fused bone between the wrist and the knuckles. It is a smallish bone in most birds, generally fla ...

, rendering it club-like. The

metacarpal In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones ( wrist bones), which articulate ...

is enlarged and bowed distally with thickened walls, while the

ulna The ulna or ulnar bone (: ulnae or ulnas) is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the Radius (bone), radius, the forearm's other long ...

and

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

have been modified as well. From its maximum femur diameter of 8.7 mm, it has been estimated that the Jamaican Ibis weighed about 2 kg (70 oz).

Clubbed wing function

Ornithologist Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

s speculate that the wings were used as weapons, in the manner of a club or

flail Flail may refer to: * Flail (tool), an agricultural implement for threshing * Flail (weapon) A flail is a weapon consisting of a striking head attached to a handle by a flexible rope, strap, or chain. The chief tactical virtue of the flail i ...

, similar to the adaptations found in some

mantis shrimp Mantis shrimp are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 400 million years ago, with more than 520 extant species of mantis shrimp known. All li ...

s (Stomatopoda: Gonodactyloidea) that possess a club-like distally inflated dactyl used to strike prey and other shrimps. Among birds, this adaption seems unique. In birds, adaptations of the wing that are advantageous in the context of fighting represent an example of contingency in which species find different solutions to the same problem as a result of random variations. Clubbed-wing-drawing

Distribution

The Jamaican ibis was endemic to Jamaica. Bones have been excavated from several caves, including the Long Mile Cave, the Swansea Cave, the Jackson's Bay Cave and the Red Hills Fissure. Bones from

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

claimed to be of this genus were later identified as those of a

limpkin The limpkin (''Aramus guarauna''), also called carrao, courlan, and crying bird, is a large wading bird related to rails and cranes, and the only extant species in the family Aramidae. It is found mostly in wetlands in warm parts of the America ...

. Jamaica and Cuba have never been linked, so it is improbable that a flightless species could reach a different island.

References

{{Taxonbar, from=Q2521346 Holocene extinctions Extinct animals of Jamaica Threskiornithidae Ibises Fossil taxa described in 1977 Extinct flightless birds Extinct birds of the Caribbean