Trias Greenfinch
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The Trias greenfinch (''Chloris triasi'') is an extinct passerine from the family of
finch The true finches are small to medium-sized passerine birds in the family Fringillidae. Finches have stout conical bills adapted for eating seeds and nuts and often have colourful plumage. They occupy a great range of habitats where they are usua ...
es (Fringillidae). The fossil remains were unearthed in the Cuevas de los Murciélagos near San Andrés y Sauces in the north of
La Palma La Palma (, ), also known as ''La isla bonita'' () and officially San Miguel de La Palma, is the most north-westerly island of the Canary Islands, Spain. La Palma has an area of making it the fifth largest of the eight main Canary Islands. The ...
, Canary Islands. The species epithet commemorates Spanish palaeontologist Miquel Trías who collected the holotype together with
Josep Antoni Alcover Josep is a Catalan masculine given name equivalent to Joseph (Spanish ''José''). People named Josep include: * Josep Bargalló (born 1958), Catalan philologist and former politician * Josep Bartolí (1910-1995), Catalan painter, cartoonist and w ...
in July 1985.


Description

The
holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...
is an almost complete cranium with both pterygoids but lacking
mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
,
quadrate bone The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper pa ...
s, and the
palatine process of maxilla In human anatomy of the mouth, the palatine process of maxilla (palatal process), is a thick, horizontal process of the maxilla. It forms the anterior three quarters of the hard palate, the horizontal plate of the palatine bone making up the re ...
. The paratypes include a proximal fragment of a right humerus, a distal fragment of a right humerus with a prominent fragmented epicondyle, a left
ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...
lacking the
epiphyseal plate The epiphyseal plate (or epiphysial plate, physis, or growth plate) is a hyaline cartilage plate in the metaphysis at each end of a long bone. It is the part of a long bone where new bone growth takes place; that is, the whole bone is alive, wit ...
, an almost complete right ulna lacking the
olecranon The olecranon (, ), is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon ...
and a complete left
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 flat ...
. The cranium length is 34,89 mm, the cranium width is 17,47 mm and the cranium height is 14,31 mm. The
maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...
length is 19,10 mm, the maxilla width is 9,67 mm, and the maxilla height is 6,71 mm. The interorbital width is 6,11 mm. The length of the carpometacarpus is 11,69 mm. The Trias greenfinch was closely related to the
European greenfinch The European greenfinch or simply the greenfinch (''Chloris chloris'') is a small passerine bird in the finch family Fringillidae. This bird is widespread throughout Europe, North Africa and Southwest Asia. It is mainly resident, but some north ...
(''Chloris chloris''). However, its head was larger and broader and its bill was about 30 percent larger. Its legs were very long and robust, but compared to the greenfinch its wings were shorter. This might have been an adaption to more terrestrial habits in the laurel forests.


Biology

Its large bill suggests the assumption that its main diet included large seeds. The shorter wings might have reduced its flight ability which wasn't necessary due to the lack of predators on La Palma.


Extinction

The fossil material is from layers which are dated to the Late Pleistocene. However, it might have become extinct in the early Holocene when the first human settlers, accompanied by
cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...
s and rats, arrived at the Canary Islands.


References

*Josep Antoni Alcover & F. Florit: ''Una nueva especie de Carduelis (Fringillidae) de La Palma'' In: Vieraea 17 (1987):p 75-86 *Julian Pender Hume, Michael Walters: Extinct Birds. A & C Black, London 2012. :p 316 {{Taxonbar, from=Q1516212 Chloris (bird) Late Quaternary prehistoric birds Birds of the Canary Islands Holocene extinctions Fossil taxa described in 1987 Extinct birds of Atlantic islands