''Tingmiatornis'' (meaning "bird that flies") is a genus of flighted and possibly diving
ornithurine
Ornithurae (meaning "bird tails" in Greek) is a natural group which includes the common ancestor of ''Ichthyornis'', ''Hesperornis'', and all modern birds as well as all other descendants of that common ancestor.
Classification
Ernst Haeckel coi ...
bird from the High Arctic of
Canada. The genus contains a single species, ''T. arctica'', described in 2016, which lived during the
Turonian epoch of the
Cretaceous.
Description
Given the small number of bones that are referrable to ''Tingmiatornis'', it is difficult to infer much about the animal. However, the thickness of the
cortical bone (on average, ) and the relative length of the
humerus
The humerus (; ) 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 and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
suggest that it was apparently a flighted bird that also likely was capable of diving, similar to the possible
hesperornithine ''
Pasquiaornis''. ''Tingmiatornis'' can be differentiated from the latter by numerous traits including larger size, a more globe-shaped
dorsal condyle on the humerus, an
olecranon process of the
ulna that does not project outward as strongly, as well as a smaller bicipital tubercle of the ulna.
''Tingmiatornis'' also differs from ''
Ichthyornis'' in the following ways: the
head of the humerus is more rounded and projects further downwards; the deltopectoral crest of the humerus is narrower and curves slightly forwards; the secondary pneumotricipital
fossa
Fossa may refer to:
Animals
* Fossa (animal), the common name of a carnivoran mammal of genus ''Cryptoprocta'' endemic to Madagascar
* ''Fossa'', the Latin genus name of the Malagasy civet, a related but smaller mammal endemic to Madagascar
Pla ...
of the humerus is deeper; and the expansion of the humerus known as the bicipital crest is longer, with a slightly convex bottom edge that transitions smoothly into the rest of the humerus rather than being hatchet-shaped.
Discovery and naming
The remains of ''Tingmiatornis'' were found on
Axel Heiberg Island
Axel Heiberg Island ( iu, ᐅᒥᖕᒪᑦ ᓄᓈᑦ, ) is an uninhabited island in the Qikiqtaaluk Region, Nunavut, Canada. Located in the Arctic Ocean, it is the 32nd largest island in the world and Canada's seventh largest island. According ...
in the High Arctic of
Nunavut
Nunavut ( , ; iu, ᓄᓇᕗᑦ , ; ) is the largest and northernmost Provinces and territories of Canada#Territories, territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the ''Nunavut Act'' ...
,
Canada, in an as-of-yet unnamed -thick layer of
Turonian rock between the
Kanguk Formation
The Kanguk Formation is a geological formation in the Northwest Territories and Nunavut, Canada whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; ...
and the
Strand Fiord Formation
The Strand Fiord Formation is a Late Cretaceous volcanic component, located on northwestern and west-central Axel Heiberg Island, Nunavut, Canada. The formation contains flood basalts which are found on western Axel Heiberg Island at Dragon Cliff ...
. Radiometric dating places the age of these rocks at 92 Mya.
The type specimen consists of a left humerus labelled with the specimen number NUFV 1960, kept in the Nunavut Fossil Vertebrate Collection of the
Canadian Museum of Nature
The Canadian Museum of Nature (french: Musée canadien de la nature; CMN) is a national natural history museum based in Canada's National Capital Region. The museum's exhibitions and public programs are housed in the Victoria Memorial Museum Bui ...
. Other specimens referred to ''Tingmiatornis'' consist of a partial humerus (UR 00.200, stored at the
University of Rochester) and ulna (NUFV 1838).
The genus name of ''Tingmiatornis'' incorporates the
Inuktitut
Inuktitut (; , syllabics ; from , "person" + , "like", "in the manner of"), also Eastern Canadian Inuktitut, is one of the principal Inuit languages of Canada. It is spoken in all areas north of the tree line, including parts of the provinces o ...
word "Tingmiat", which means "those that fly". The species name, ''arctica'', refers to the specimens being discovered in the High Arctic.
Paleoecology
A number of other vertebrates are known alongside ''Tingmiatornis'' from the locality on
Axel Heiberg Island
Axel Heiberg Island ( iu, ᐅᒥᖕᒪᑦ ᓄᓈᑦ, ) is an uninhabited island in the Qikiqtaaluk Region, Nunavut, Canada. Located in the Arctic Ocean, it is the 32nd largest island in the world and Canada's seventh largest island. According ...
, including
champsosaurs that measured in length;
fish including
gar,
bowfin
The bowfin (''Amia calva'') is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being the sole surviving species of the Halecomorphi ...
s, members of the extinct
Vidalamiinae
The Amiidae are a family of basal ray-finned fishes. The bowfin is the only species to survive today, although additional species in all four subfamilies of Amiidae are known from Jurassic, Cretaceous, and Eocene fossils.
Bowfins are now found ...
, and indeterminate
teleosts;
turtles, including ''
Aurorachelys
''Aurorachelys'' is an extinct genus of turtle which existed in Canada (Nunavut) during the late Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of ...
'',
''
Borealochelys'', indeterminate
eucryptodires, and indeterminate
trionychids;
and juvenile
elasmosaurs, known from teeth.
During the
Turonian, the area would have been a large, freshwater to brackish bay
situated at approximately 71° paleolatitude.
This habitat, which had a mean temperature of approximately 14 °C,
would have been an ideal nesting ground for ''Tingmiatornis'', although no eggs or nests have been found at the locality to date. The bowfins that swam in the surrounding water, which likely measured in length, may have competed with ''Tingmiatornis'' for smaller fish, if the latter was a diving bird. ''Tingmiatornis'' may also have fished at night, much like the modern
Western grebe; at this latitude, it would have experienced approximately two months of continuous darkness per year.
During the Late Cretaceous, high latitudes appeared to have been dominated by
ornithurines
Ornithurae (meaning "bird tails" in Greek) is a natural group which includes the common ancestor of ''Ichthyornis'', ''Hesperornis'', and all modern birds as well as all other descendants of that common ancestor.
Classification
Ernst Haeckel coi ...
as opposed to the more
basal
Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''.
Science
* Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure
* Basal (medicine), a minimal level that is nec ...
enantiornithines.
This may be due to ornithurines exploiting more aquatic niches
or having higher growth rates in highly seasonal climates;
the latter likely did not apply as strongly to ''Tingmiatornis'' due to the warm local climate.
References
{{Taxonbar, from=Q28050733
Prehistoric ornithurans
Turonian life
Late Cretaceous birds of North America
Fossils of Canada
Paleontology in Nunavut
Fossil taxa described in 2016