Gargantuavis
| Gargantuavis | ||||||
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Holotype (MDE C3-525), synsacrum and parts of the ilium from Gargantuavis philoinos |
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| Temporal occurrence | ||||||
| Upper Campanium to Lower Maastrichtian | ||||||
| around 72 million years | ||||||
| Locations | ||||||
| Systematics | ||||||
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| Scientific name | ||||||
| Gargantuavis | ||||||
| Buffetaut & Le Loeuff , 1998 | ||||||
| Art | ||||||
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Gargantuavis was a genus of flightless birds from the Upper Cretaceous of southern France and northern Spain. The only known species of the so far monotypical genus is Gargantuavis philoinos .
Etymology and history of research
The generic name Gargantuavis refers to Gargantua, one of the two giants from François Rabelais ' novel cycle Gargantua and Pantagruel in combination with the Latin " avis " for "bird". The additional species “ philoinos ” (ancient Greek for “one who loves wine”) refers to the location of the holotype in the middle of extensive vineyards.
Initial reports about the fossil remains of a large bird from the Upper Cretaceous of southern France date back to 1995. The first description of the genus and type species was carried out in 1998 by Éric Buffetaut and Jean Le Loeuff based on the holotype (MDE C3-525) of Synsacrums and parts of Os Ilium and a fragment of a right femur . The authors assigned the find material to the Ornithothoraces .
2009, by Gerald Mayr , raised concerns whether it is at Gargatuavis indeed or a bird that the fossil remains not perhaps rather a representative of azhdarchiden pterosaurs are due, these doubts were Buffetaut and Le Loeuff 2010, however, resolved in a more comprehensive analysis.
In 2013 and 2015 there was a description of further fossil evidence from different sites in southern France and in 2017 also from northern Spain. In 2014, Anusuya Chinsamy and others also published the results of histological examinations on the femur fragment described in 1998 together with the holotype. In 2016, Buffetaut and Delphine Angst summarized the information about Gargantuavis philoinos known at the time in a review article .
Fossil record
Gargantuavis is only partially covered with corresponding fossil material. Several pelvic fragments can be assigned to one and the same taxon with some certainty , but with other isolated skeletal elements (thighbones, cervical vertebrae) this is not directly possible and the assignment to Gargantuavis is essentially based on the absence of anatomical contradictions and the assumption that only one species inhabited the same habitat by large, flightless birds.
All fossils that have so far been assigned to Gargantuavis come from terrestrial sediments that are stratigraphically assigned to the upper Campanium to the lower Maastrichtian :
- Without inventory number: fragment of a synsacrum; Fox-Amphoux (SO-France)
- MDE C3-525 ( holotype ): synsacrum and fragments of the ilium; Stratum typicum: Marnes de la Maurine Formation, Campagne-sur-Aude (SW France)
- MDE A-08: fragment of a femur; Villespassans (SW France)
- MC-MN 478: cervical vertebra; Cruzy (SW France)
- BN 758 and BN 763: fragments of synsacrum and ilium as well as a possible rib fragment; Fox-Amphoux (SO-France)
- MCNA 2583: fragment of a synsacrum; Laño (Northern Spain)
- MN 1335: complete but much smaller thigh bone; Cruzy (SW France)
features
Buffetaut and Le Loeuff describe Gargantuavis philoinos as a flightless bird about the size of an African ostrich . The body mass is estimated on the basis of the circumference of the thigh bone (MDE A-08) at 141 kg and is thus also approximately in the range of an African ostrich. The second, smaller thigh bone (MN 1335) indicates a body mass of around 57 kg and overall dimensions that roughly correspond to those of an emus . The differences are attributed either to ontogenetic variations and / or to a possible sexual dimorphism .
The description of the characteristics of the species follows the diagnosis by Buffetaut and Angst, 2016:
The pelvis is wide with the acetabulum very far forward . The sturdy and relatively short synsacrum is curved on the abdomen and consists of at least ten completely fused vertebrae. The two iliac bones do not touch each other at the back, above the synsacrum. A clearly developed antitrochanter (an articular surface on the iliac bone of birds that acts as a counterpart to the greater trochanter of the femur) lies posterodorsal to the acetabulum. The pelvic bones are heavily pneumatized .
The cervical vertebrae are heterocoel, ie the joint surfaces between the individual vertebral bodies are saddle-shaped, concave in one plane and convex in the plane perpendicular to it. The caudal articular surface is unusually narrow.
The thighbone is strong. There is a rounded “ crista trochanterica ”. A posterior trochanter as in Archeopteryx or representatives of the enantiornithes , however, seems to be missing.
Systematics
The systematic position of Gargantuavis philoinos within the Ornithothoraces is unclear. Belonging to the enantiornithes seems unlikely due to the known anatomical features. Buffetaut and Angst suspect a closer relationship with the Ornithurae in 2013, but due to the lack of suitable fossil evidence, this remains speculation, as the authors themselves later emphasize and Gargantuavis is considered to be " incertae sedis " within the Ornithothoraces.
Paleecology
During the Upper Cretaceous Period, Central Europe consisted of a collection of larger and smaller, largely isolated islands ("European Cretaceous Archipelago"). The habitat of Gargantuavis was in the southwestern section of this archipelago and was at times subdivided into individual sub-islands and at times united to form a larger land mass ("Ibero-Armorican Island"). There are no fossil records of Gargantuavis from other areas of the European Cretaceous Archipelago and the genus seems to be endemic to the "Ibero-Armorican Island" .
A detailed analysis of the site at Cruzy characterizes the deposit area as an interwoven river system under "tropical" climatic conditions with alternating dry and wet seasons, the latter regularly leading to short-term flooding events. This finding is in good agreement with the histological analyzes on the thigh bone MDE A-08, which indicated a prolonged growth phase with rhythmically changing growth spurts and growth stops. This is possibly an adaptation as a local island end with the prevailing climatic conditions and the resulting food supply.
So far available knowledge of the anatomy of Gargantuavis suggests that the bird was flightless. The pelvis, which is relatively wide compared to its length, is interpreted as an indication of graviportal locomotion. Gargantuavis shouldn't have been a particularly fast runner. How the genus was able to prevail in an isolated island environment in which large carnivorous theropods lived at the same time is still unclear.
Since essential parts of the skeleton, in particular the skull and jaw, are completely unknown, no reliable information on diet can be given.
literature
- Delphine Angst, Éric Buffetaut: Palaeobiology of Giant Flightless Birds. 296 p., ISTE Press and Elsevier, 2017, ISBN 978-1-78548-136-9 (reading sample)
Individual evidence
- ↑ a b c d e f g h i Éric Buffetaut & Delphine Angst: The Giant Flightless Bird Gargantuavis philoinos from the Late Cretaceous of southwestern Europe: A Review. In: A. Khosla & SG Lucas (Eds.): Cretaceous Period: Biotic Diversity and Biogeography. New Mexico Museum of Natural History and Science Bulletin, Vol. 71, pp. 45–50, 2016 (digitized version)
- ↑ a b c d e Éric Buffetaut and Jean Le Loeuff: A new giant ground bird from the Upper Cretaceous of southern France. In: Journal of the Geological Society of London , Vol. 155, pp. 1-4, 1998. ( PDF ).
- ↑ a b Éric Buffetaut, Jean Le Loeuff, Patrick Mechin and Annie Mechin-Salessy: A large French Cretaceous bird. In: Nature , Vol. 377, p. 110, 1995. (digitized version)
- ↑ Gerald Mayr: Paleogene Fossil Birds. , 262 S., Springer Verlag, 2009 (reading sample)
- ↑ Éric Buffetaut & Jean Le Loeuff: Gargantuavis philoinos: Giant bird or giant pterosaur? In: Annales de Paléontologie , Vol. 96, Issue 4, pp. 135–141, 2010. (Abstract)
- ↑ a b c Éric Buffetaut and Delphine Angst: New evidence of a giant bird from the Late Cretaceous of France. In: Geological Magazine , Vol. 150, Issue 1, pp. 173–176, 2013 ( PDF )
- ↑ a b c Éric Buffetaut, Delphine Angst, Patrick Mechin & Annie Mechin-Salessy: New remains of the giant bird Gargantuavis philoinos from the Late Cretaceous of Provence (south-eastern France). In: PALAEOVERTEBRATA , Vol. 39, No. (2) -e3, pp. 1–6, 2015. (pdf)
- ↑ a b Delphine Angst, Éric Buffetaut, José Carmelo Corral & Xabier Pereda-Suberbiola: First record of the Late Cretaceous giant bird Gargantuavis philoinos from the Iberian Peninsula. In: Annales de Paléontologie , Vol. 103, Issue 2, pp. 135-139, 2017. (digitized version)
- ↑ a b Anusuya Chinsamy, Éric Buffetaut, Aurore Canoville & Delphine Angst: Insight into the growth dynamics and systematic affinities of the Late Cretaceous Gargantuavis from bone microstructure. In: Naturwissenschaften , Vol. 101, pp. 447–452, 2014. (available)
- ^ A b Delphine Angst & Éric Buffetaut: Palaeobiology of Giant Flightless Birds. 296 p., ISTE Press and Elsevier, 2017.
- ↑ a b Z. Csiki-Sava, E. Buffetaut, A. Ősi, X. Pereda-Suberbiola & St. L. Brusatte: Island life in the Cretaceous - faunal composition, biogeography, evolution, and extinction of land-living vertebrates on the Late Cretaceous European archipelago. In: ZooKeys. Vol. 469, 2015, pp. 1–161, doi: 10.3897 / zookeys.469.8439
- ↑ Franck Smektala, Éric Buffetaut & Jean-François Deconinck: Rivers as repositories for fossil vertebrates: a case study from the Upper Cretaceous of southern France. In: Proceedings of the Geologists' Association , Vol. 125, Issue 5-6, pp. 567-577, 2014. (Abstract)
Web links
- Gargantuavis philoinos on dinodata
- Gargantuavis on fossilworks