''Caiuajara'' is an extinct
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
tapejarid pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...
from the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
period (
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...
stage) of
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
. It is known from a single
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
, ''Caiuajara dobruskii''.
Discovery and naming
In 1971, the labourers Alexandre Dobruski and his son João Gustavo Dobruski found pterosaur fossils in a field near
Cruzeiro do Oeste
Cruzeiro do Oeste is a municipality in the state of Paraná in the Southern Region of Brazil.
See also
*List of municipalities in Paraná
This is a list of the municipalities in the state of Paraná (PR), located in the South Region of Brazil. ...
in the south of Brazil, in the state of
Paraná.
The finds were in 2011 brought to the attention of paleontologists Paulo C. Manzig and Luiz C. Weinschütz.
In 2014, the
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
''Caiuajara dobruskii'' was named and described by
Paulo Manzig,
Alexander Kellner,
Luiz Weinschütz,
Carlos Fragoso,
Cristina Vega,
Gilson Guimarães,
Luiz Godoy,
Antonio Liccardo,
João Ricetti
João is the Portuguese equivalent of the given name John. The diminutive is Joãozinho and the feminine is Joana. It is widespread in Portuguese-speaking countries. Notable people with the name are enumerated in the sections below.
Kings
* ...
and
Camila de Moura. The generic name refers to the geological
Caiuá Group
Caiuá is a municipality in the state of São Paulo in Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 milli ...
and the related genus ''
Tapejara''. The
specific name Specific name may refer to:
* in Database management systems, a system-assigned name that is unique within a particular database
In taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany), the two-part (bino ...
honors the discoverers.
The
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...
, CP.V 1449, was found in a sandstone layer of the
Goio-Erê Formation
The Goio-Erê Formation is a geological formation in Brazil. It is sometimes thought to be deposited between the Turonian and Campanian stages of the Late Cretaceous, but an Aptian-Albian date has also been proposed. It primarily consists of sand ...
, of
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...
age, in the
Paraná Basin.
[''Caiuajara'']
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org It consists of a partial skeleton including the skull, lower jaws, neck vertebrae and wing elements. Many hundreds of bones have been discovered, concentrated in several bone beds, and representing at least forty-seven individuals but probably many more. In the total assembly, all elements of the skeleton are present. The bones have been three-dimensionally preserved, not compressed, but are only rarely articulated. The individuals found are often juveniles; adult animals are much rarer, only represented by two skulls and three humeri. Good specimens have been assigned as
paratypes, the more fragmentary ones have been referred.
The paratypes are: CP.V 865: a snout, rear of the mandibula, right jugal, vertebrae, ribs and metatarsals; CP.V 867: a snout and limb bones; CP.V 868: a snout, wing elements and other postcrania; CP.V 869: a vertebral column, right arm, coracoid, breastbone, wing phalanges, belly ribs, pelvic elements and a right thighbone; CP.V 870: a shoulder girdle with the humeri; CP.V 871: a right shoulder girdle with right arm elements; CP.V 872: s partial skeleton including the skull, lower jaws, right arm, neck vertebrae and additional limb elements; CP.V 873: a snout and finger phalanges; CP.V 999: a partial skull; CP.V 1001: a slab with a partial skull, lower jaws and postcrania of at least three individuals; CP.V 1003: a partial skull and symphysis; CP.V 1004: a snout; CP.V 1005: a partial crested skull with the complete mandibula; CP.V 1006: a partial crested skull lacking the snout combined with postcrania; CP.V 1023: a snout and postcrania; CP.V 1024: a skull and postcrania of at least three juveniles; CP.V 1025: a thighbone; CP.V 1026: a thighbone; CP.V 1450: a slab containing at least fourteen juveniles; CP.V 2003: a skull with lower jaws and articulated wing elements; UEPG/DEGEO/MP-4151: a slab with two skulls and postcrania; and UEPG/DEGEO/MP-4152: a snout with postcrania.
Most specimens are part of the collection of the ''Centro Paleontológico'' of the ''
Universidade do Contestado''.
Description
The largest individuals of ''Caiuajara'' had an estimated
wingspan
The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of ...
of . The species had a large toothless head with, in adult individuals, an enormous shark fin-shaped crest on the snout.
The describing authors established several distinguishing unique traits,
autapomorphies. The tip of the snout is strongly oriented to below, at 142 to 149°, relative to the edge of the upper jaw. The rear ascending branches of the premaxillae on their midline form an elongated bony rim projecting to below into the nasoantorbital fenestra, the large skull opening in the side of the snout. In the concave upper rear of the symphysis, the fronts of the lower jaws grown together, a rounded depression is present. The front outer edge of the quadrate shows a longitudinal groove. Below the front part of the nasoantorbital fenestra, a depression is present in the upper jaw edge.
Additionally, ''Caiuajara'' shows a unique combination of traits that are themselves not unique. The lower edge of the eye socket is rounded. At a maximal occlusion, the gap between the upper and lower jaw is wider than with other tapejarines. The pteroid on its bottom surface shows a conspicuous depression lacking a pneumatic opening.
Phylogeny
''Caiuajara'' was assigned to the
Tapejaridae, more precisely the
Tapejarinae. It shares several traits with the tapejarids, such as a crest running from the front snout to the back of the head; an elongated nasoantorbital fenestra occupying over 40% of total skull length; and a large boss on the front edge of the coracoid. A typical tapejarine trait is the down-turned snout tip. A
cladistic analysis showed that ''Caiuajara'' is a possible
sister species of ''
Tupandactylus
''Tupandactylus'' (meaning "Tupan finger", in reference to the Tupi thunder god) is a genus of tapejarid pterodactyloid pterosaur from the Early Cretaceous Crato Formation of Brazil.
History
''Tupandactylus imperator'' is known from four nearl ...
''. In 2014, ''Caiuajara'' was the geologically youngest known tapejarid (aside from the possible tapejarid ''
Bakonydraco galaczi
''Bakonydraco'' is a genus of pterodactyloid pterosaur from the Late Cretaceous period (Santonian stage) of what is now the Csehbánya Formation of the Bakony Mountains, Iharkút, Veszprém, western Hungary.
Etymology
''Bakonydraco'' was na ...
'') and also the most southern one known. This expansion of their known range was seen as an indication that tapejarids had a global distribution. Moreover, ''Caiuajara'' is the first pterosaur found in the south of Brazil.
A phylogenetic analysis conducted in 2019 by Kellner (one of the describers of ''Caiuajara'') and colleagues recovered ''Caiuajara'' within the tribe
Tapejarini, sister taxon to sister taxon to three other genera: ''
Europejara
''Europejara'' is a genus of tapejarid pterosaur from the Early Cretaceous period of Spain. The type species, type and only species known is ''Europejara olcadesorum''.
Discovery and naming
In 2012, the type species ''Europejara olcadesorum'' ...
'', ''Tapejara'', and ''Tupandactylus''.
Paleobiology
The
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
of ''Caiuajara'' was a desert with dunes. The layers in which the fossils were found had been deposited in a lake in the desert; probably the bones had been exposed at the surface around the lake for a time and were then by storms blown into it, eventually sinking to the bottom. Possibly the same storms caused many individuals to die together; this could also have been the result of droughts. A succession of layers shows that the lake was likely inhabited by the pterosaurs for a great length of time, although it is also possible they visited the lake during regular migrations. Fossil plants — tapejarids are often assumed to have been herbivores — have not been found, so there are no direct indications about the food source. Likewise, remains of
invertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
have not been discovered.
The large concentrations of fossils, among pterosaurs very rare and only equaled by those found of the Argentine form ''
Pterodaustro'', were by the describers seen as proof of a gregarious lifestyle, ''Caiuajara'' living in colonies. The many specimens also allowed to determine a growth series, the first such an ontogenetic sequence for pterosaurs of which it is nearly certain that it really represented a single species. The age of the exemplars can be determined, not just from size but also by the degree of ossification, especially of the breastbone, the long bones and the wrist, and the fusion of the shoulder blade and coracoid into a
scapulocoracoid. It showed that juvenile individuals, the smallest specimens of which have a wingspan of about , generally had the same proportions as adults. Especially important is that their humeri are not proportionally smaller and their humeral deltopectoral crests, the attachments of the main flight muscles, are not less developed, attaining a size of 38 to 40% of the humeral shaft length. This suggests that they were
precocial, taking wing almost as soon as they hatched; parental care must have been limited. This might have been typical of all derived pterosaurs. The snout crest however, strongly changed during growth. It became much taller and also much more steeply inclined, from about 115° to 90°. Although the snout as a whole also became more massive, the snout tip inclination relative to the jaw edge remained the same. At the back of the skull an additional projection developed. Furthermore, the dentary crest on the lower jaw strongly increased in size. No specimens have been found lacking the snout crest, indicating that ''Caiuajara'' was in this respect not
sexually dimorphic and casting doubt on the hypothesis that pterosaurs normally were.
See also
*
List of pterosaur genera
*
Timeline of pterosaur research
References
External links
Discovery News about the fossil find
{{Portal bar, Paleontology, Cretaceous, Brazil
Tapejaromorphs
Late Cretaceous pterosaurs of South America
Turonian life
Cretaceous Brazil
Fossils of Brazil
Paraná Basin
Fossil taxa described in 2014
Taxa named by Alexander Kellner