text: saint croix macaw the saint croix macaw ( ara ) is an extinct species of parrot . the last populations lived on the caribbean islands saint croix and puerto rico . it was originally described by alexander wetmore in 1937 based on a subfossil limb bone unearthed by l. j. korn in 1934 from a kitchen midden at an amerindian archeological site on saint croix . a second specimen was described by storrs l. olson and edgar j. máiz lópez based on various limb and shoulder bones excavated from a similar site on puerto rico , while a possible third specimen from montserrat has been reported . the species is one of two medium - sized macaws of the caribbean , the other being the smaller cuban red macaw ( ara tricolor ) . its bones are distinct from amazon parrots as well as from the other medium - sized but geographically distant lear 's macaw ( anodorhynchus ) and blue - throated macaw ( ara ) . the natural range is unknown because parrots were regularly traded between islands by indigenous people . like other parrot species in the caribbean , the extinction of the saint croix macaw is believed to be linked to the arrival of humans in the region . name and etymology alexander wetmore named the species . an alternative incorrect spelling is autochthones , which comes from the ancient greek word ( — autos " self " and — " earth " ) meaning " born of the earth " . of a name are termed as lapsus ( an accidental misspelling ) . an obvious error in the original publication containing the description of a species may be corrected by a later " emendation " with suitable justification . taxonomy wetmore placed the saint croix macaw in the macaw genus ara based on a single tibiotarsus , a placement confirmed by olson who reexamined the bone . the discovery of a second specimen by máiz lópez at puerto rico consisting of several bones confirmed this placement . the saint croix macaw is distinguished from other macaws because of the intermediate size of the tibiotarsus and carpometacarpus . olson and máiz lópez determined that the size of this species is only comparable to geographically distant macaws , namely the lear 's macaw ( anodorhynchus ) from brazil and the blue - throated macaw ( ara ) from bolivia . their detailed analysis of these and the other bones showed distinct differences from those species , particularly from the genus anodorhynchus . based on this , authorities generally recognize the saint croix macaw as a valid species . the saint croix macaw and the smaller cuban red macaw ( ara tricolor ) are the only two caribbean macaw species that have been described based on physical remains . in addition , seven entirely hypothetical extinct macaw species from various caribbean islands have been described based only on written accounts . of the hypothetical species , the geographically nearest range is of the lesser antillean macaw ( ara guadeloupensis ) from guadeloupe . according to wetmore , taxonomic affinities with these hypothetical extinct species are unknown . description the subfossil left tibiotarsus ( holotype , usnm ) described by wetmore was of an immature but full - grown bird . wetmore described the bone as similar to the tibiotarsus of ara tricolor , with a larger transverse width , but more slender compared with larger macaws . the slender proportions of the bone and more elongated ridges about the proximal end distinguish the species from the amazon parrots . the bones found by máiz lópez ( usnm ) include the left coracoid ( missing a portion of the bone 's head ) , the proximal and distal ends of the left humerus , the proximal end of the right radius , the left carpometacarpus ( missing one metacarpal ) , the left femur ( lacking the distal end ) , the right tibiotarsus ( lacking part of the proximal articular surface ) , and the proximal fragment and worn distal portion of the left tibiotarsus . olson and máiz lópez examined the bones and showed that they differed from amazon parrot bones . the tibiotarsus has a narrower internal condyle ( the round prominences at the end of a bone ) and a distinctive inner cnemial crest ( a ridge at the front side of the head ) that is more pointed and extends further proximally . the carpometacarpus is proportionally much longer with a process on the alular metacarpal that is not curved proximally . the femur has a proportionally larger head while the process ( a bony elevation ) and the attachment of pronator brevis ( one of the two pronation muscles in the wing ) on the humerus are more proximal . the elongated coracoid has a relatively narrow shaft and the ventral lip of the glenoid facet ( equivalent to the glenoid fossa of mammals ) is more protruded . olson and máiz lópez showed that the saint croix macaw is within the same size range as the blue - throated macaw and the lear 's macaw . the length of the tibiotarsus is shorter than in the blue - throated macaw but longer than in the lear 's macaw , while the lengths of the coracoid , carpometacarpus , and femur are smaller . in addition to the size , they observed that the pectoral attachment on the humerus is less excavated while the capital groove ( a groove separating two parts of the head of the humerus ) is wider ; the head of the femur is more massive and when seen from the posterior side , more excavated under the head , neck , and trochanter . furthermore , the more robust shaft of the femur sets it specifically apart from the lear 's macaw while the tibiotarsus is more robust with a flared distal extremity . distribution bones of the species have been excavated at two islands in the caribbean , saint croix and puerto rico . the location at saint croix is a pre - columbian amerindian village site near the current town of concordia , near the southwest cape . the bones from puerto rico were excavated from an inland village of the saladoid indians that was located at the eastern bank of the río , north - east of the current city of ponce . a possible third location is montserrat , where a nearly complete coracoid was excavated ( uf ) . the bone of this specimen is slightly smaller than the bone of the puerto rico specimen , and could therefore be within the range of the cuban red macaw ( ara tricolor ) ; it has not been assigned to either species . although the species had only been found in st. croix and puerto rico , in both cases it was recovered from amerindian village sites . williams and steadman consider it possible that the species may have been native to st. croix , but olson and máiz lópez regard this as unlikely , noting that parrots , important to the indigenous people , were likely to have been transported between islands . this makes it difficult to determine the natural geographical origins of the parrots known only from subfossil remains found in the west indian region . extinction the extinction of birds in the caribbean occurred during three periods . the first period was linked to the sea - level rise after the end of the last ice age . the second period of extinction is linked to the arrival of the amerindians , while the third extinction period is linked to the arrival of the europeans . although the exact causes of the extinction of the saint croix macaw are unknown , it is likely related to arrival of the humans in the region . the presence of the bones in kitchen middens suggests that the species was hunted for food . the bones found by máiz lópez are dated to about 300 ce , which implies that the extinction of the saint croix macaw occurred after that . archeological context the species was originally described by wetmore based on material excavated in 1934 by l. j. korn from a pre - columbian amerindian kitchen midden ( dump for domestic waste ) near concordia , saint croix , without specifying the age of the bone . in 1987 , máiz lópez found several bones of a single bird at the hernández colón archeological site on the eastern bank of the río in south central puerto rico the archeological side in the semi - arid southern foothills is a pre - columbian saladoid village of approximately 15 , 000 m2 ( 3 . 7 acres ) situated on an alluvial terrace . máiz lópez found the bones in a kitchen midden in the layer that corresponded with the base and beginning of the phase , which is stylistically related to the hacienda grande ceramic style that lasted globally from about 200 bce to 400 ce . radiocarbon dating of charcoal samples indicate that the phase started locally around 300 ce .