Concornis
Encyclopedia
Concornis was an enantiornithine bird. It lived during the Early Cretaceous
, in the late Barremian
stage or about 127-125 million years ago, and its remains are known from the Calizas de La Huérguina Formation at Las Hoyas
, Cuenca province, Spain
. The single known species
Concornis lacustris was described from remains of one individual skeleton which is not quite complete but bears feather impressions.
This was a smallish bird, measuring maybe 13 cm (12.5 in) without tail http://dml.cmnh.org/2001Jul/msg01069.html. Its weight was probably some 75g or more, possibly over 100 g. Nothing is known about its beak, but it was almost certainly still toothed and somewhat snout-like as in its relatives. It was probably an accomplished flyer for its time, though perhaps not as nimble and somewhat lacking in stamina compared to modern birds. It is not known whether it had an alula
and it must have possessed a long, narrow pygostyle
not known to be associated with Neornithes-like rectrices. The legs were fairly long and neither dedicated to perching on branches nor to running on the ground; it had a large hallux
as is generally absent in terrestrial
birds. Its habitus
seems to have been most similar to a small wader
- between a Ruddy Turnstone
and an Eurasian Dotterel
in size maybe - or a buttonquail
, but with a ling hind toe, very stout legs, and the enantiornithine beak.
; these were at that time little-known and, as the primitive Iberomesornis
was not yet considered to belong there either, contained only very advanced taxa. With more and more enantiornithine material becoming known, the placement of C. lacustris in this group was eventually verified. In fact, despite its early age, C. lacustris seems by no means primitive among the Enantiornithes.
It is sometimes considered a member of the Enantiornithiformes and related to Enantiornis
; others reject this placement. A cladistic analysis including many enantiornithine taxa places it in the "Cathayornithiformes", grouping with Sinornis (or Cathayornis) and, surprisingly, Neuquenornis volans which was hitherto believed to belong to a different lineage of Euenantiornithes
. Whichever of the two competing hypotheses may be correct, they provide evidence that the Euenantiornithes were accomplished flyers capable of crossing ocean
s, as in either case close relatives of Concornis inhabited South America
.
A relationship with Sinornis/Cathayornis is suggested mainly by a peculiarly autapomorphic sternum
. There is a keel that is small compared to that of modern birds, "Y"-shaped, and the end of the sternum bears deep notches like in the Chinese bird.
and habits
of Concornis lacustris are by and large conjectural. Its legs and flight apparatus suggest it was a truly multifuncional generalist
bird able to bound through vegetation, run on the ground, and fly equally well. Compared to living birds adapted to each of these ecological niches, it would have certainly been inferior. It was found in an aquatic
environment, suggesting it occupied at least partly a "shorebird" niche, and given its size would presumably have fed on small invertebrate
s like insect
s or crustacean
s. There were terrestrial predators around in its habitat - including its non-avian
theropod relatives and crocodilians - from which Concornis would have found it far easier to fly up to some porch than to run away.
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, in the late Barremian
Barremian
The Barremian is an age in the geologic timescale between 130.0 ± 1.5 Ma and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch...
stage or about 127-125 million years ago, and its remains are known from the Calizas de La Huérguina Formation at Las Hoyas
Las Hoyas
Las Hoyas is a Cretaceous Konservat-Lagerstätten located near the city of Cuenca, Spain.It is dated as Barremian , and is mostly known from its exquisitely preserved dinosaurs, especially enantiornithines.- Taphonomy :...
, Cuenca province, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. The single known species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
Concornis lacustris was described from remains of one individual skeleton which is not quite complete but bears feather impressions.
This was a smallish bird, measuring maybe 13 cm (12.5 in) without tail http://dml.cmnh.org/2001Jul/msg01069.html. Its weight was probably some 75g or more, possibly over 100 g. Nothing is known about its beak, but it was almost certainly still toothed and somewhat snout-like as in its relatives. It was probably an accomplished flyer for its time, though perhaps not as nimble and somewhat lacking in stamina compared to modern birds. It is not known whether it had an alula
Alula
The alula, or bastard wing, is a small projection on the anterior edge of the wing of modern birds. The alula is the freely moving first digit, a bird's "thumb," and is typically covered with three to five small feathers, with the exact number depending on the species...
and it must have possessed a long, narrow pygostyle
Pygostyle
Pygostyle refers to a number of the final few caudal vertebrae fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these....
not known to be associated with Neornithes-like rectrices. The legs were fairly long and neither dedicated to perching on branches nor to running on the ground; it had a large hallux
Hallux
In tetrapods, the hallux is the innermost toe of the foot. Despite its name it may not be the longest toe on the foot of some individuals...
as is generally absent in terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
birds. Its habitus
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
seems to have been most similar to a small wader
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
- between a Ruddy Turnstone
Ruddy Turnstone
The Ruddy Turnstone is a small wading bird, one of two species of turnstone in the genus Arenaria. It is now classified in the sandpiper family Scolopacidae but was formerly sometimes placed in the plover family Charadriidae...
and an Eurasian Dotterel
Eurasian Dotterel
The Eurasian Dotterel , or in Europe just Dotterel, is a small wader in the plover family of birds.It breeds in the Arctic tundra of northern Eurasia, from Norway to eastern Siberia, and on suitable mountain plateaus such as the Scottish highlands and the Alps...
in size maybe - or a buttonquail
Buttonquail
Buttonquail or hemipodes are members of a small family of birds, Turnicidae, which resemble, but are unrelated to, the quails of Phasianidae. They inhabit warm grasslands in Asia, Africa, Europe, and Australia...
, but with a ling hind toe, very stout legs, and the enantiornithine beak.
Systematics
Initially it was believed to be more primitive than EnantiornithesEnantiornithes
Enantiornithes is an extinct group of primitive birds. They were the most abundant and diverse avialans of the Mesozoic. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over 50 species of Enantiornithines have been named, but some...
; these were at that time little-known and, as the primitive Iberomesornis
Iberomesornis
Iberomesornis is a monotypic genus of enantiornithine bird of the Cretaceous of Spain.In 1985 the fossil of Iberomesornis was discovered by Armando Díaz Romeral in the Early Cretaceous Calizas de La Huérguina Formation at Las Hoyas, Cuenca Province, east central Spain, which dates to the late...
was not yet considered to belong there either, contained only very advanced taxa. With more and more enantiornithine material becoming known, the placement of C. lacustris in this group was eventually verified. In fact, despite its early age, C. lacustris seems by no means primitive among the Enantiornithes.
It is sometimes considered a member of the Enantiornithiformes and related to Enantiornis
Enantiornis
Enantiornis is a genus of predatory enantiornithine bird. The type and only currently accepted species E. leali is from Late Cretaceous rocks at El Brete, Argentina....
; others reject this placement. A cladistic analysis including many enantiornithine taxa places it in the "Cathayornithiformes", grouping with Sinornis (or Cathayornis) and, surprisingly, Neuquenornis volans which was hitherto believed to belong to a different lineage of Euenantiornithes
Euenantiornithes
Euenantiornithes is a superorder of Cretaceous birds. They are considered to contain the more advanced taxa of the Enantiornithes, the dominant group of birds during the late Mesozoic...
. Whichever of the two competing hypotheses may be correct, they provide evidence that the Euenantiornithes were accomplished flyers capable of crossing ocean
Ocean
An ocean is a major body of saline water, and a principal component of the hydrosphere. Approximately 71% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
s, as in either case close relatives of Concornis inhabited South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
.
A relationship with Sinornis/Cathayornis is suggested mainly by a peculiarly autapomorphic sternum
Sternum
The sternum or breastbone is a long flat bony plate shaped like a capital "T" located anteriorly to the heart in the center of the thorax...
. There is a keel that is small compared to that of modern birds, "Y"-shaped, and the end of the sternum bears deep notches like in the Chinese bird.
Ecology
The habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
and habits
Habit (biology)
Habit, when used in the context of biology, refers to the instinctive actions of animals and the natural tendencies of plants.In zoology, this term most often refers to specific behavioral characteristics, even when directly related to physiology...
of Concornis lacustris are by and large conjectural. Its legs and flight apparatus suggest it was a truly multifuncional generalist
Generalist
Generalist may refer to:* a person with a wide array of knowledge, the opposite of which is a specialist.* a physician who is focused on primary care and is not a specialist in a certain medical field...
bird able to bound through vegetation, run on the ground, and fly equally well. Compared to living birds adapted to each of these ecological niches, it would have certainly been inferior. It was found in an aquatic
Aquatic ecosystem
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems....
environment, suggesting it occupied at least partly a "shorebird" niche, and given its size would presumably have fed on small invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s like insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s or crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s. There were terrestrial predators around in its habitat - including its non-avian
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
theropod relatives and crocodilians - from which Concornis would have found it far easier to fly up to some porch than to run away.