Corvus impluviatus
| Corvus impluviatus | ||||||||||||
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Lower jaw (mandible) and tip of upper beak (rostrum) of Corvus impluviatus |
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| Scientific name | ||||||||||||
| Corvus impluviatus | ||||||||||||
| Olson & James , 1991 |
High-billed crow is an extinct species of bird in the family Corvidae . It belongs to a group of crows endemic to the Hawaiian Islands, of which only the Hawaiian crow ( Corvus hawaiiensis ) has survived to this day. Corvus impluviatus is known only from subfossil material.
The type material was recovered in 1977 by Storrs Olson , Helen F. James, Aki Sinoto and others with the help of diving equipment from a flooded cave at Barbers Point on Oahu .
features
The holotype consists of an almost perfectly preserved skeleton and contains the skull with the maxilla, palatine bones , cheekbones , both wings legs , both square legs , the left frontal bone , the mandible, twelve cartilage rings of the trachea , the Syrinxtrommel, the wishbone, sternum, ten complete ribs and some ribs fragments, ten cervical vertebrae, three caudal vertebrae, the shoulder blade , the Ulne that Rabe legs , the humerus, the radii that Carpometacarpi , the carpal bones, the Digitus alulae , the left femur, both fibula bones, both Tibiotarsi , the right tarsometatarsus and twelve toe bones. There are also three incomplete skeletons.
Corvus impluviatus was a large species of crow. Compared to the great-billed crow ( Corvus woodfordi ) and the bougainville crow ( Corvus meeki ), the beak was deeper. Compared to the thick-billed crow ( Corvus macrorhynchos ), the beak was shorter and deeper. Compared to the common raven ( Corvus corax ), the beak was deeper and the bridge of the nose wider. Compared to the Hawaiian crow ( Corvus hawaiiensis ), the beak was shorter. Compared to the big-billed crow, the common raven and the Chatham raven ( Corvus moriorum ), the nostrils were less elongated from front to back. The membrane in the nasal cavities was more ossified. The septum between the eye sockets was not broken. Compared to the Chatham raven, the beak was more curved and the skull window was smaller or nonexistent. In contrast to the other Hawaiian endemic species Corvus hawaiiensis and Corvus viriosus , the upper beak was higher and more curved. The bridge of the nose and the sides of the nose were wider.
die out
The cause and timing of the extinction are still unclear. It is believed that the first Polynesian settlers on the Hawaiian Islands hunted the birds, destroyed the habitat through fire and other activities, or the introduced rats could have eaten the eggs of the species.
etymology
The type epithet is derived from the Latin word impluvium and means " the skylight in the roof of the atrium of a Roman house ". It refers to the nature of the type locality that the team of palaeontologists reached by jumping through an opening in the cave ceiling into the clear water. The root word impluvius means rain , alluding to the watery environment of the cave.
literature
- Olson, Storrs L .; James, Helen F. (1991): Descriptions of Thirty-Two New Species of Birds from the Hawaiian Islands: Part II. Passeriformes . Ornithological Monographs 46: 1-91. PDF online .
Web links
- Jan TenBruggencate: " Oahu sinkholes yield extinct birds ". In: The Honolulu Advertiser , Aug. 7, 2007.