Post by Eaglehawk on Jul 18, 2019 3:55:51 GMT
Aldiomedes angustirostris
Skull of Aldiomedes angustirostris, n. gen. et sp. from the late Pliocene of South Taranaki, New Zealand (holotype, NMNZ S.046313)
Temporal range: Late Pliocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Diomedeidae G.R. Gray 1840
Genus: †Aldiomedes
Species: †Aldiomedes angustirostris
Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains show they once occurred there and occasional vagrants are found. Albatrosses are among the largest of flying birds, and species of the genus Diomedea (great albatrosses) have the longest wingspans of any extant birds, reaching up to 3.7 m (12 ft). The albatrosses are usually regarded as falling into four genera, but disagreement exists over the number of species.
Aldiomedes angustirostris is an albatross. The type species is A. angustirostris.
Scientists describe an almost complete albatross skull from the pliocene epoch
by Senckenberg Research Institute and Natural History Museum
Nearly complete fossil skull of the new albatross species (above) in comparison to the Black-footed Albatross, one of the smallest extant albatrosses (below). Credit: Jean-Claude Stahl, Te Papa.
Senckenberg ornithologist Gerald Mayr, in conjunction with his colleague Alan Tennyson of the Te Papa Museum in New Zealand, describe a previously unknown, extinct albatross species from the Pliocene. The bird, which lived about 3 million years ago, only reached approximately 90 percent of the size of the smallest modern albatrosses. However, the fossil's most remarkable trait is the unusually narrow beak, which suggests that the new species mainly fed on fish. The diet of modern albatrosses, by contrast, is dominated by squid. The fossil discovery thus indicates a higher diversity in the feeding ecology of extinct albatrosses and raises the question why the fish-eating forms ultimately went extinct. The study is published today in the scientific journal Ibis.
Extant albatrosses are known for their considerable size: the largest species reach a wingspan of more than 3 meters. However, while living albatrosses are among the most iconic pelagic birds, little is known about the evolutionary history of these characteristic flyers, and fossils are extremely rare.
The new species, described as Aldiomedes angustirostris, is represented by an almost completely preserved skull that was discovered in 2011 by a private collector in the Tangahoe Formation on New Zealand's North Island. The marine sediments of this fossil site are known for their rich Pliocene fauna.
"The new species we described is clearly smaller than all modern albatrosses," explains Dr. Gerald Mayr of the Senckenberg Research Institute in Frankfurt, and he continues, "Small albatross species are already known from the Eocene and Miocene epochs, but the new fossil is the youngest and most complete of these small forms and the only one of which a skull has been found."
The avian skull examined by Mayr and his colleague Alan Tennyson differs from all other known albatross species not only in its size; the shape of the beak also deviates from the norm. "The slender beak resembles that of modern seabirds that feed on fish," explains Mayr. The ornithologists therefore assume that the newly discovered species preferred a diet of fish, unlike modern albatrosses who primarily hunt for squid.
The fossil discovery shows that albatrosses had a more diversified feeding ecology in the past. However, it remains an enigma why these small, fish-eating species ultimately went extinct. "It is possible that they shared similar ecological niches with other seabirds such as boobies or cormorants during the Pliocene and ultimately succumbed to competition with these birds" assumes Mayr and adds in closing, "However additional fossils from the avifaunas of that time are needed to properly test this hypothesis."
phys.org/news/2019-07-scientists-albatross-skull-pliocene-epoch.html
Journal Reference:
Gerald Mayr et al. A small, narrow‐beaked albatross from the Pliocene of New Zealand demonstrates a higher past diversity in the feeding ecology of the Diomedeidae, Ibis (2019). DOI: 10.1111/ibi.12757
Abstract
We describe a nearly complete, three‐dimensionally preserved skull of a new albatross species from the late Pliocene (3.0–3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a small‐sized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smaller‐sized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various non‐procellariiform seabird groups.
onlinelibrary.wiley.com/doi/full/10.1111/ibi.12757
Skull of Aldiomedes angustirostris, n. gen. et sp. from the late Pliocene of South Taranaki, New Zealand (holotype, NMNZ S.046313)
Temporal range: Late Pliocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Diomedeidae G.R. Gray 1840
Genus: †Aldiomedes
Species: †Aldiomedes angustirostris
Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains show they once occurred there and occasional vagrants are found. Albatrosses are among the largest of flying birds, and species of the genus Diomedea (great albatrosses) have the longest wingspans of any extant birds, reaching up to 3.7 m (12 ft). The albatrosses are usually regarded as falling into four genera, but disagreement exists over the number of species.
Aldiomedes angustirostris is an albatross. The type species is A. angustirostris.
Scientists describe an almost complete albatross skull from the pliocene epoch
by Senckenberg Research Institute and Natural History Museum
Nearly complete fossil skull of the new albatross species (above) in comparison to the Black-footed Albatross, one of the smallest extant albatrosses (below). Credit: Jean-Claude Stahl, Te Papa.
Senckenberg ornithologist Gerald Mayr, in conjunction with his colleague Alan Tennyson of the Te Papa Museum in New Zealand, describe a previously unknown, extinct albatross species from the Pliocene. The bird, which lived about 3 million years ago, only reached approximately 90 percent of the size of the smallest modern albatrosses. However, the fossil's most remarkable trait is the unusually narrow beak, which suggests that the new species mainly fed on fish. The diet of modern albatrosses, by contrast, is dominated by squid. The fossil discovery thus indicates a higher diversity in the feeding ecology of extinct albatrosses and raises the question why the fish-eating forms ultimately went extinct. The study is published today in the scientific journal Ibis.
Extant albatrosses are known for their considerable size: the largest species reach a wingspan of more than 3 meters. However, while living albatrosses are among the most iconic pelagic birds, little is known about the evolutionary history of these characteristic flyers, and fossils are extremely rare.
The new species, described as Aldiomedes angustirostris, is represented by an almost completely preserved skull that was discovered in 2011 by a private collector in the Tangahoe Formation on New Zealand's North Island. The marine sediments of this fossil site are known for their rich Pliocene fauna.
"The new species we described is clearly smaller than all modern albatrosses," explains Dr. Gerald Mayr of the Senckenberg Research Institute in Frankfurt, and he continues, "Small albatross species are already known from the Eocene and Miocene epochs, but the new fossil is the youngest and most complete of these small forms and the only one of which a skull has been found."
The avian skull examined by Mayr and his colleague Alan Tennyson differs from all other known albatross species not only in its size; the shape of the beak also deviates from the norm. "The slender beak resembles that of modern seabirds that feed on fish," explains Mayr. The ornithologists therefore assume that the newly discovered species preferred a diet of fish, unlike modern albatrosses who primarily hunt for squid.
The fossil discovery shows that albatrosses had a more diversified feeding ecology in the past. However, it remains an enigma why these small, fish-eating species ultimately went extinct. "It is possible that they shared similar ecological niches with other seabirds such as boobies or cormorants during the Pliocene and ultimately succumbed to competition with these birds" assumes Mayr and adds in closing, "However additional fossils from the avifaunas of that time are needed to properly test this hypothesis."
phys.org/news/2019-07-scientists-albatross-skull-pliocene-epoch.html
Journal Reference:
Gerald Mayr et al. A small, narrow‐beaked albatross from the Pliocene of New Zealand demonstrates a higher past diversity in the feeding ecology of the Diomedeidae, Ibis (2019). DOI: 10.1111/ibi.12757
Abstract
We describe a nearly complete, three‐dimensionally preserved skull of a new albatross species from the late Pliocene (3.0–3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a small‐sized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smaller‐sized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various non‐procellariiform seabird groups.
onlinelibrary.wiley.com/doi/full/10.1111/ibi.12757