Ludodactylus

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Ludodactylus
Ludodactylus sibbicki (Holotype SMNK PAL 3828)

Ludodactylus sibbicki (Holotype SMNK PAL 3828)

Temporal occurrence
Aptium
126.3 to 112.9 million years
Locations
Systematics
Archosauria
Flugsaurier (Pterosauria)
Short-tailed pterosaur (Pterodactyloidea)
Ornithocheiroidea
Ornithocheiridae
Ludodactylus
Scientific name
Ludodactylus
Frey , Martill & Buchy , 2003
Art
  • Ludodactylus sibbicki

Ludodactylus is a genus of short-tailed pterosaurs from the Ornithocheiridae group . The only known species of the so far monotypical genus is Ludodactylus sibbicki from the Crato formation (Santana group) of the Araripe basin of Ceará in northeastern Brazil .

Etymology and history of research

The generic name is made up of " Ludo- " from the Latin " ludus " ("game"; used here in the sense of "toy") in combination with the ending " -dactylus ", latinized after, which is often used by representatives of the pterosaurs the ancient Greek δάκτυλος ( dáktylos = "finger"; used here in the sense of "pterosaur"). The generic name refers to the Pteranodon -like occipital ridge and the toothed jaws, a combination of features previously only known from toy figures in which Pteranodon -like pterosaurs were incorrectly provided with teeth to give them a grimmer appearance. Only the discovery of Ludodactylus gave these fantasy products in the toy industry a real basis.

The additional species " sibbicki " honors the British " Paleoart " artist John Sibbick . The species name (literally: “Sibbicks toy finger”) can be translated accordingly as “Sibbicks toy pterosaur”.

The holotype and so far the only fossil record for Ludodactylus sibbicki came into the hands of science through commercial channels. The quarries in the vicinity of Nova Olinda in the Brazilian state of Ceará were given as the location . The lithology of the fossil-bearing rock slab and a fossil of a small fish of the genus Dastilbe also preserved on it confirm the information and the specimen could be assigned to the Nova Olinda member within the Crato formation . The latter is placed in the aptium ( Lower Cretaceous ; about 126.3–112.9  Ma ) on the basis of palynological findings .

The original fossil is now under the inventory number SMNK PAL 3828 at the State Museum of Natural History in Karlsruhe , where the final preparation of the fossil was also carried out. It was first described in 2003 by Eberhard Frey , David M. Martill and Marie-Céline Buchy .

features

Artistic reconstruction of life

From Ludodactylus sibbicki only an almost complete skull including the lower jaw is known. Unless otherwise stated, the description of the features is based on the initial description by Frey et al. , 2003.

The skull of the holotype SMNK PAL 3828 has a total length of a little more than 47 cm and the wingspan of the animal is estimated to be around 4 m.

The external nasal opening (naris externa) and the antorbital window (fenestra antorbitalis) are fused to form a common nasoantorbital window that identifies Ludodactylus as a representative of the pterodactyloidea . The most noticeable feature is a crest of bone that starts from the parietal bone , is laterally flattened and directed backwards, which is strongly reminiscent of a corresponding feature of Pteranodon . Ludodactylus , however, has 23 pairs of teeth in the upper jaw and 17 pairs of teeth in the lower jaw, while the representatives of the genus Pteranodon and their closest relatives were entirely toothless. The row of teeth in the upper jaw extends approximately to the middle, those of the lower jaw to the front quarter of the nasoantorbital window. The dentition shows Ludodactylus as a representative of the Ornithocheiridae. A sagittal bone crest in the area of ​​the premaxilla , as is found in many other representatives of the Ornithocheiridae, does not occur in Ludodactylus . A corresponding, even if only very weakly pronounced, bone crest in the area of ​​the lower jaw is mentioned in the first description, but is strongly doubted by later editors.

 Ornithocheiroidea  
 Pteranodontia  
 Pteranodontoidea  




 Ornithocheiridae


   

 Istiodactylidae



   

 Lonchodectes



   

 Hongshanopterus



   

 Pteranodontidae



   

 Nyctosauridae 



 Azhdarchoidea  



 Tapejaridae


   

 Bennettazhia




 Neoazhdarchia  


 Dsungaripteridae


   

 Thalassodrominae



   

 Chaoyangopteridae


   

 Azhdarchidae






Template: Klade / Maintenance / Style
Internal systematics of the ornithocheiroidea, simplified from Upchurch et al., 2015.

The lacrimal bone has a thorn-like, dorsoventrally flattened process (" spina lacrimalis "), which protrudes backwards into the area of ​​the eye socket . The lacrimal foramen has a rounded triangular outline, with one corner oriented ventrally .

Systematics

Ludodactylus sibbicki was originally described by Frey and co-authors as a representative of the Ornithocheiridae within the group of Ornithocheiroidea .

In 2005, Veldmeijer et al. the possibility in the room that Ludodactylus could be a junior synonym of Brasileodactylus . However, this approach was not pursued further and most authors consider Ludodactylus to be a valid, independent taxon .

Wang et al. interpreted Ludodactylus as a sister taxon to Guidraco in 2012 and concluded from this a paleobiogeographical connection between the Jiufotang Formation in northeast China and the Crato Formation in Brazil. However, more recent and more comprehensive phylogenetic analyzes could not confirm this relationship and show Ludodactylus and Guidraco in clades that are clearly separated from one another .

 Ornithocheiridae  




 Annexueridae


   

 Ludodactylus



   

 Brasileodactylus



   

 Cearadactylus



   

 Guidraco


   

 Zhenyuanopterus


   

 Boreopterus





Template: Klade / Maintenance / Style
Systematic position of Ludodactylus within the Ornithocheiridae, according to Upchurch et al., 2015.

The adjacent cladograms show in a simplified form the systematic position of the Ornithocheiridae within the Ornithocheiroidea as well as the position of Ludodactylus within the Ornithocheiridae according to an analysis published in 2015 by Paul Upchurch and co-authors. Ludodactylus , together with Brasileodactylus and Cearadactylus , occupies a position as sister taxon of the Annexueridae ( Annexuera , Liaoningopterus , Tropeognathus , Ornithocheirus and Coloborhynchus ). Guidraco , Zhenyuanopterus and Boreopterus , on the other hand, form an independent subclade within the Ornithocheiridae. The family relationships within the ornithocheiroidea and thus also the systematic position of Ludodactylus are by no means fully clarified.

Paleecology

Location and geological map of the Araripe Basin in northeastern Brazil. Nova Olinda Member and Crato Formation are part of the Santana group (dark blue).

The rocks of the Nova Olinda member within the Crato Formation were deposited in an extensive lake or lagoon in the northeastern area of ​​the Araripe Basin. The current distribution of the finely laminated, microcritical plate limestone of the Nova Olinda member shows that the water body is at least 75 × 50 km in size. The lithology and geochemistry of the plate limestone suggest a stably stratified body of water with a well-aerated, near-surface freshwater layer and stagnant, anoxic and / or hypersalinous deep waters.

The vertebrate fauna of the Nova Olinda member is dominated by fish, especially small fish of the genus Dastilbe . Remains of pterosaurs are amazingly the second most common group of vertebrate fossils. More than 30 scientifically described pterosaur remains can be assigned to at least five different genera. Fossils of other vertebrates are much rarer and include various amphibians, the crocodile Susisuchus , the snake-like scaled reptile Tetrapodophis or the enantiornithine bird Cratoavis .

Shell remnants from molluscs are not present in the Nova Olinda member. On the other hand, well-preserved plant remains and fossils of mostly land-living arthropods are often found .

With the exception of the fish, a large part of the animal and plant remains were transported via rivers or as wind cargo to the dump of the Nova Olinda member. Accordingly, they represent fauna and flora in the hinterland, which can be characterized as an arid area with a chaparral- like vegetation cover.

Way of life

Ludodactylus sibbicki probably ate piscivor , like most of the other members of the Ornithocheiridae .

Taphonomy

Despite the frequency and the mostly good state of preservation of the pterosaur fossils of the Nova Olinda member, it has not yet been possible to recover a complete specimen (skull + postcranial skeleton). The fossil remains are either more or less complete postcranial skeletons without skulls or, as in the case of SMNK PAL 3828, as isolated skulls with no relation to any postcranial skeletal elements. The separation of head and body can be explained by the long drifting of the carcasses on the water surface. With increasing putrefaction, the relatively heavy skull first detaches from the body and sinks to the bottom of the water. The trunk and limbs, on the other hand, continue to drift, aided by the highly pneumatized bone structure of the pterosaurs, and only later sink into another place when the degree of decomposition is higher.

Interpretation of the plant residue on SMNK PAL 3828

In addition to the skull of Ludodactylus sibbicki and a fish of the genus Dastilbe , SMNK PAL 3828 also shows a fossil plant residue . The plant fossil belongs to a type of leaf fossil that occurs relatively frequently in the Nova Olinda member of the Crato Formation. Complete specimens are elongated, lanceolate, with a smooth, slightly concave base and a sharp tip. You can add up to reach a length of about 1 m and the authors of the first description of Ludodactylus sibbicki refer among other things to a certain resemblance to the leaves of yucca . Similar plant remains from the Crato formation were described in 2005 as Welwitschiophyllum brasiliense and assigned to the Welwitschiaceae family .

The remnant of the leaf lies in the area of ​​the pterosaur's lower jaw and approximately across it, but not above or below the bone, but between the two branches of the lower jaw. The leaf base is well preserved and lies between the pterosaur's upper and lower jaw. The sharp tip of the leaf is missing. The distal end of the leaf is anterior to the lower jaw and is very frayed and frayed.

Frey et al. in the context of the first description of Ludodactylus sibbicki put forward the hypothesis that the pterosaur probably thought the leaf was a potential prey and he tried to eat it. According to her assumption, the leaf got caught laterally between the left branch of the lower jaw and the tongue and subsequently pierced the pterosaur's throat pouch with its sharp tip. The frayed end of the leaf can be traced back to the unsuccessful attempts of the pterosaur to remove the foreign body. In this context, the authors refer to recent cases in which individual individuals of the chile pelican ( Pelecanus thagus ) suffer a similar fate when attempting to eat coarse plastic garbage and mostly starve to death, unable to continue to acquire food.

In this context, Mark P. Witton refers to the position of the hyoid bone , that thin, tuning fork-shaped bone which in SMNK PAL 3828 lies ventrally away from the lower jaw and entirely on the remnant of the leaf. He describes the hypothesis of the first person describing it as “not unfounded” (“not untenable”), but notes that it can neither be proven nor refuted and is therefore of little value for an understanding of the pterosaur's way of life.

Individual evidence

  1. ↑ a b c d e f g h i j k E. Frey, DM Martill, M.-C. Buchy: A new crested ornithocheirid from the Lower Cretaceous of northeastern Brazil and the unusual death of an unusual pterosaur. In: E. Buffetaut, J.-M. Mazin (Ed.): Evolution and Palaeobiology of Pterosaurs. In: Geological Society of London - Special Publications. Volume 217, 2003, pp. 55-63 ( preview ).
  2. ↑ RBJ Benson, RA Frigot, A. Goswami, B. Andres, RJ Butler: Competition and constraint drove Cope's rule in the evolution of giant flying reptiles. In: nature Communications. Volume 5, Article Number 3567, 2014, Supplementary Data 1, doi : 10.1038 / ncomms4567 .
  3. ↑ X. Wang, T. Rodrigues, Sh. Jiang, X. Cheng, AWA Kellner: An Early Cretaceous pterosaur with an unusual mandibular crest from China and a potential novel feeding strategy. In: nature - Scientific Reports. Volume 4, Article Number 6329, 2014, 9 S, doi : 10.1038 / srep06329 .
  4. ↑ a b c d P. Upchurch, B. Andres, RJ Butler, PM Barrett: An analysis of pterosaurian biogeography: implications for the evolutionary history and fossil record quality of the first flying vertebrates. In: Historical Biology. Volume 27, number 6, 2015, pp. 697-717 ( digitized version ).
  5. ↑ AJ Veldmeijer, M. Signore, H. Meijer: brasileodactylus (Pterosauria, Pterodactyloidea, Anhangueridae); to update. In: Cranium. Volume 22, Number 1, 2005, pp. 45-56. ( Digitized version ).
  6. ↑ X. Wang, AWA Kellner, Sh. Jiang, X. Cheng: New toothed flying reptile from Asia: close similarities between Early Cretaceous pterosaur faunas from China and Brazil. In: Natural Sciences. Volume 99, number 4, 2012, pp. 249-257, doi : 10.1007 / s00114-012-0889-1 ( digitized version ).
  7. ^ B. Andres, JM Clark, X. Xu: The Earliest Pterodactyloid and the Origin of the Group. In: Current Biology. Volume 24, 2014, pp. 1011-1016, doi : 10.1016 / j.cub.2014.03.030 .
  8. ↑ a b c D. M. Martill, RF Loveridge, JA Ferreira Gomes de Andrade, AH Cardoso: An unusual occurrence of amber in laminated limestones: The Crato Formation Lagerstätte (Early Cretaceous) of Brazil. In: Palaeontology. Volume 48, Number 6, 2005, pp. 1399-1408 ( digitized version ).
  9. ↑ U. Heimhofer, D. Ariztegui, M. Lenniger, St. P. Hesselbo, DM Martill, AM Rios-Netto: Deciphering the depositional environment of the laminated Crato fossil beds (Early Cretaceous, Araripe Basin, North ‐ eastern Brazil). In: Sedimentology. Volume 57, number 2, 2010, pp. 677-694, doi : 10.1111 / j.1365-3091.2009.01114.x .
  10. ^ A b c M. P. Witton: A new Azhdarchoid Pterosaur from the Crato Formation (Lower Cretaceous, Aptian?) Of Brazil. In: Palaeontology. Volume 51, Number 6, 2008, pp. 1289-1300, doi : 10.1111 / j.1475-4983.2008.00811.x .
  11. ↑ St. W. Salisbury, E. Frey, DM Martill, M.-C. Buchy: A new crocodilian from the Lower Cretaceous Crato Formation of north-eastern Brazil. In: Palaeontographica. Section A: Palaeozoology - Stratigraphy, Volume 270, 2003, pp. 3–47 ( digitized version ).
  12. ↑ DM Martill, H. Tischlinger, NR Longrich: A four-legged snake from the Early Cretaceous of Gondwana. In: Science. Volume 349, number 6246, 2015, pp. 416-419, doi : 10.1126 / science.aaa9208 ( digitized version ).
  13. ^ IS Carvalho, FE Novas, FL Agnolín, MP Isasi, FI Freitas, JA Andrade: A new genus and species of enantiornithine bird from the Early Cretaceous of Brazil. In: Brazilian Journal of Geology. Volume 45, number 2, 2015, pp. 161–171, doi : 10.1590 / 23174889201500020001 ( digitized version ).
  14. ↑ J. Bestwick, DM Unwin, RJ Butler, DM Henderson, MA Purnell: Pterosaur dietary hypotheses: a review of ideas and Approaches. In: Biological Reviews. Volume 93, number 4, 2018, pp. 2021-2048, doi : 10.1111 / brv.12431 ( PDF file ).
  15. ↑ AJ Veldmeijer, M. Witton, I. Nieuwland: Pterosaurs: Flying Contemporaries of the Dinosaurs. Sidestone Press, Leiden, 2012, ISBN 978-90-8890-093-8 , p. 53 ( reading sample ).
  16. ^ RA Elgin, E. Frey: A nearly complete ornithocheirid pterosaur from the Aptian (Early Cretaceous) Crato Formation of NE Brazil. In: Acta Palaeontologica Polonica. Volume 57, number 1, 2012, pp. 101–110 ( digitized version ).
  17. ^ DL Dilcher, ME Bernardes de Oliveira, D. Pons, TA Lott: Welwitschiaceae from the Lower Cretaceous of Northeastern Brazil. In: American Journal of Botany. Volume 92, number 8, 2005, pp. 1294-1310 ( digitized version ).
  18. ^ MP Witton: Pterosaurs in Mesozoic food webs: a review of fossil evidence. In: DWE Hone, MP Witton, DM Martill (Eds.): New Perspectives on Pterosaur Palaeobiology. Geological Society of London, Special Publication Number 455, 2018, ISBN 978-1-78620-317-5 , pp. 7-23 ( excerpt ).

Remarks

  1. ↑ A clear assignment of the plant residue of SMNK PAL 3828 to this taxon has not been proven in the specialist literature.
  2. ↑ Leaf fragments of this type, with a well-preserved base and frayed leaf end, are frequent enough in the Crato formation that they are discussed separately in the first description of Welwitschiophyllum brasiliense and the corresponding conservation form is also shown.

Web links

Commons : Ludodactylus  - collection of images, videos and audio files