Tetrapodophis

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Tetrapodophis
Temporal range: Early Cretaceous Aptian
Tetrapodophis amplectus 3483.jpg
Fossil in Bürgermeister-Müller-Museum
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family:† Dolichosauridae
Genus:† Tetrapodophis
Martill et al., 2015
Type species
†Tetrapodophis amplectus
Martill et al., 2015

Tetrapodophis (Greek meaning "four-footed snake") is an extinct genus of lizard from the Early Cretaceous (Aptian) aged Crato Formation of Brazil. It has an elongate snake-like body, with four limbs. Tetrapodophis has been considered by some authors to be one of the oldest members of Ophidia (snakes and their extinct relatives). [1] [2] [3] However, this classification has been disputed by some other authors, [4] [5] [6] who identify Tetrapodophis as a dolichosaurid much less closely related to snakes.

Contents

Description

Hindlimbs Tetrapodophis hindlimbs.jpg
Hindlimbs

Tetrapodophis possesses small yet well-developed fore- and hindlimbs like a lizard and a long body similar to a snake, around 19.5 cm (7.7 in) in length. [6] Nevertheless, it shares many characteristics with modern snakes, including an elongate body, short tail, broad belly scales, a skull with a short snout and long braincase, curved jaws, and sharp hooked teeth. BMMS BK 2-2 contains bones of another animal in its gut, indicating that Tetrapodophis was carnivorous like most snakes. Other features such as short neural spines suggest that Tetrapodophis was adapted to burrowing, lending support to the hypothesis that snakes evolved in terrestrial environments (another hypothesis posits that they evolved in aquatic environments). [2] The high number of vertebrae (upwards of 150) in Tetrapodophis and snakes is not seen in other burrowing reptiles with elongate bodies and reduced or absent limbs, meaning that it is most likely not an adaptation for a serpentine form of movement. [1]

Discovery and controversy

The type species, Tetrapodophis amplectus, was named in 2015 on the basis of a complete skeleton (BMMS BK 2-2) preserved on a limestone slab in the Bürgermeister Müller Museum in Solnhofen, Germany, which was labeled as "unknown fossil" until its importance was recognized by paleontologist David Martill [7] when he visited Germany in 2012, [8] and housed in a private collection in a private in a museum in Solnhofen. [8] The fossil had in the hands of the private collector for "several decades" prior to the publication. [9] While no locality information was provided for the specimen, [9] based on characteristics of the rock it is thought to come from the Early Cretaceous Crato Formation of Northeast Brazil. [9] Brazil's laws do not allow the removal of fossils from its territory since 1942, nor that studies on them be conducted without the participation of at least one Brazilian scientist. Due to a lack of information regarding the provenance of the fossil, it was possible that the fossil had been illegally exported from Brazil. [8] This caused controversy among Brazilian paleontologists, [10] and sparked a legal investigation by the Brazilian government. [8] According to lead author Martill, fossils from the Crato Formation are widely illegally collected and exported from Brazil due to corruption in the country, and are found in fossil shops and museums all over the world. [11]

When the fossil was collected is unknown. Dave Martill asserted in an interview to a Brazilian journalist that it was possible that the fossil was exported prior to 1942, but stated that ultimately he didn't "care a damn how [or when] the fossil came from Brazil", saying that it was irrelevant to its scientific signficance. Martill stated that he was "critical of all laws that interfere with the science of paleontology; and blanket bans on fossil collecting are indiscriminatory and only hinder science ... They also lead to xenophobia -- Brazil fossils for Brazilians, British fossils for Brits. It should be fossils for all. No countries existed when the animals were fossilized." When asked why he did not include a Brazilian scientist on the study, Martill remarked that he was unaware of any Brazilian snake researchers when wriitng the study (though he later became aware of one following the controversy), but followed with "But what difference would it make? I mean, do you want me also to have a black person on the team for ethnicity reasons, and a cripple and a woman, and maybe a homosexual too just for a bit of all round balance? … If you invite people because they are Brazilian then people will think that every Brazilian author on a scientific paper is there because he is Brazilian and not because he is a clever scientist." [10] Martill remarked several years later in 2020 that he felt his comments in the interview were poorly worded. [12] Nicholas Longrich, a co-author of the study, remarked that he would like to see the fossil returned to Brazil. [8]

Aside from the export issues, the fact that the specimen was in a private collection when described also caused controversy, and the owner of the fossil reportedly made it difficult for later researchers to study the specimen. [13] In 2024, the fossil of Tetrapodophis was donated to National Museum of Brazil. [14]

Classification

A phylogenetic analysis published alongside the original 2015 description of Tetrapodophis places it as a close relative of other lizards, but outside the crown group Serpentes, meaning that Tetrapodophis branched off before the most recent common ancestor of all living snakes. Below is a cladogram from that analysis: [1]

Squamata

The interpretation of Tetrapodophis amplectus as an early fossorial snake was challenged by Caldwell et al. (2016), who considered it more likely to be a dolichosaurid squamate related to mosasaurs. [4] [15] A position supported by later analysis in 2018 [5] and in 2021. [6]

Cladogram after Caldwell et. al. 2021: [6]

Anguimorpha

However, a study in 2023 again supported its position as a stem-snake, finding it to be unrelated to mosasaurs. [3]

Related Research Articles

<span class="mw-page-title-main">Ophidia</span> Group of squamate reptiles

Ophidia is a group of squamate reptiles including modern snakes and reptiles more closely related to snakes than to other living groups of lizards.

<span class="mw-page-title-main">Lepidosauromorpha</span> Clade of reptiles

Lepidosauromorpha is a group of reptiles comprising all diapsids closer to lizards than to archosaurs. The only living sub-group is the Lepidosauria, which contains two subdivisions, Squamata, which contains lizards and snakes, and Rhynchocephalia, the only extant species of which is the tuatara.

<span class="mw-page-title-main">Pelvic spur</span> Modified reptilian appendages

Pelvic spurs are external protrusions found around the cloaca in certain superfamilies of snakes belonging to the greater infraorder Alethinophidia. These spurs are made up of the remnants of the femur bone, which is then covered by a corneal spur, or claw-like structure. This femur derives from ancestral hind limbs found in the most recent common ancestor of modern snakes and the other reptiles of the clade Toxicofera, many of which have fully functional front and hind limbs. Due to the fact that the spurs derive from the ancestral state of functional legs, but are no longer functional for locomotion specifically, these structures do meet the criteria for being considered vestigial. Nonetheless, uses for the structures have been thoroughly documented. Species that have external spurs have corresponding muscles, neurological structures, and vascularization to allow for independent movement. The spurs are more pronounced and visible in male specimens and have been observed in use during courtship behavior. The spurs are specifically used in the clasping and stimulation of females by males during courtship and mating. In certain species, males will also use their spurs to engage in combat with one another.

<i>Adriosaurus</i> Extinct genus of lizards

Adriosaurus is an extinct genus of squamate which lived in what is now Slovenia and other parts of Europe during the Late Cretaceous. It was small, snake-like reptile, with type species measuring up to 30 cm (12 in) in length. This is the first fossil record of vestigial limbs in lizards. It lost its manus and forearm completely in order to elongate its axial skeleton. These unique anatomical features led to discussions of the evolutionary patterns of limb reduction in Squamata.

<i>Kaganaias</i> Extinct genus of lizards

Kaganaias is an extinct genus of basal and oldest dolichosaur that lived in what is now Japan during the Early Cretaceous. Kaganaias was semi-aquatic and is the only known aquatic squamate known from before the Cenomanian stage of the Cretaceous. It is also the first to be found in an inland area, instead of on the coast where aquatic squamates are commonly found. Its generic name is derived from Kaga Province, the old name for the Ishikawa Prefecture where the specimens were found, while the species name hakusanensis comes from the mountain that gives its name to Hakusan the city near its find site. The geological formation in which the specimens were found, the Kuwajima Formation, stands alongside the Tetori River and has been the site of numerous other finds including molluscs, dinosaurs, fish, and pterosaurs.

<i>Carsosaurus</i> Extinct genus of lizards

Carsosaurus is a genus of extinct amphibious reptiles, in the mosasaur superfamily, containing only the species Carsosaurus marchesetti. It is known from a single individual that lived during the Upper Cretaceous in what is now Slovenia. The specimen is well-preserved, containing many different bones as well as some skin impressions and sternal cartilage. While more remains are needed to be certain, it is generally thought to belong to the Aigialosauridae. In life, it was an amphibious creature that spent most of its time on land, although its later relatives would become fully aquatic.

Parviraptor is a genus of squamate containing one species, Parviraptor estesi, from the Late Jurassic (Tithonian) or Early Cretaceous (Berriasian) Purbeck Limestone Formation of Dorset, England. A second species, Parviraptor gilmorei, was described from the Late Jurassic Morrison Formation of Western North America; it was present in stratigraphic zone 4. However, the second species was subsequently transferred to a separate genus Diablophis. An indeterminate species is known from the Bathonian aged Kirtlington Mammal Bed.

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2010.

<i>Huehuecuetzpalli</i> Extinct genus of lizards

Huehuecuetzpalli mixtecus is an extinct lizard from the Early Cretaceous Tlayúa Formation in Tepexi de Rodríguez, Central Mexico. Although it is not the oldest known lizard, Huehuecuetzpalli may be amongst the most basal members of Squamata, making it an important taxon in understanding the origins of squamates.

<span class="mw-page-title-main">Polyglyphanodontia</span> Extinct clade of lizards

Polyglyphanodontia, also known as the Borioteiioidea, is an extinct clade of Cretaceous lizards. Polyglyphanodontians were the dominant group of lizards in North America and Asia during the Late Cretaceous.

<i>Megachirella</i> Extinct genus of reptiles

Megachirella is an extinct genus of lepidosaur, possibly a stem-squamate that lived about 240 million years ago during the Middle Triassic and contains only one known species, Megachirella wachtleri. It is known from a partial skeleton discovered in the Dolomites of Northern Italy and was described in 2003.

<span class="mw-page-title-main">Ouled Abdoun Basin</span> Phosphate basin in Morocco

The Oulad Abdoun Basin is a phosphate sedimentary basin located in Morocco, near the city of Khouribga. It is the largest in Morocco, comprising 44% of Morocco's phosphate reserves, and at least 26.8 billion tons of phosphate. It is also known as an important site for vertebrate fossils, with deposits ranging from the Late Cretaceous (Cenomanian-Turonian) to the Eocene epoch (Ypresian), a period of about 25 million years.

Eophis is an early genus of stem-snake containing one species, Eophis underwoodi, from the Middle Jurassic (Bathonian) from the Forest Marble Formation of United Kingdom. It is known from a fragmentary dentary from Kirtlington Quarry. It was previously interpreted as an anguimorph lizard. The placement of Eophis as a stem snake was re-affirmed by subsequent analyses.

<span class="mw-page-title-main">Dolichosauridae</span> Extinct family of lizards

Dolichosauridae is a family of Cretaceous aquatic lizards. They are widely considered to be the earliest and most primitive members of Mosasauria, though some researchers have recovered them as more closely related to snakes.

<span class="mw-page-title-main">Mosasauria</span> Extinct squamates of the Cretaceous period

Mosasauria is a clade of aquatic and semiaquatic squamates that lived during the Cretaceous period. Fossils belonging to the group have been found in all continents around the world. Early mosasaurians like dolichosaurs were small long-bodied lizards that inhabited nearshore coastal and freshwater environments; the Late Cretaceous saw the rise of large marine forms, the mosasaurids, which are the clade's best-known members.

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2018.

Diablophis is a genus of Late Jurassic stem-snake from the Morrison Formation of North America. The type and only species, D. gilmorei was once thought to be a species of Parviraptor but is now classified as its own genus. The animal is known from multiple specimens, the holotype being LACM 4684/140572, which consists of a broken right mandible, broken right maxilla and broken axis vertebrae. A number of other specimens have also been attributed to Diablophis, including LACM 4684/140572 and LACM 5572/120732, the specimens previously attributed to Parviraptor and LACM 4684/120472.

Saurosternon is an extinct genus of neodiapsid reptile from the Late Permian of South Africa. It is based on a partial skeleton split between two slabs of sandstone from the Daptocephalus Assemblage Zone. Saurosternon was one of the earliest small lizard-like reptiles to be discovered in Permian deposits of the Karoo Supergroup, preceding later discoveries such as Paliguana, Youngina, Palaeagama, and Lacertulus. The skeleton is mostly complete, though missing the head. Most of the original bone had decayed away by the time the fossil was discovered, leaving perfect molds in the sandstone slabs. What little bone remained was removed with acid by museum preparators, and the specimen was cast with latex to reconstruct the original bone shape.

This list of fossil reptiles described in 2015 is a list of new taxa of fossil reptiles that were described during the year 2015, as well as other significant discoveries and events related to reptile paleontology that occurred in 2015.

This list of fossil reptiles described in 2016 is a list of new taxa of fossil reptiles that were described during the year 2016, as well as other significant discoveries and events related to reptile paleontology that occurred in 2016.

References

  1. 1 2 3 David M. Martill; Helmut Tischlinger; Nicholas R. Longrich (2015). "A four-legged snake from the Early Cretaceous of Gondwana". Science. 349 (6246): 416–419. Bibcode:2015Sci...349..416M. doi:10.1126/science.aaa9208. PMID   26206932. S2CID   25822461.
  2. 1 2 Lee, Michael S. Y.; Palci, Alessandro; Jones, Marc E. H.; Caldwell, Michael W.; Holmes, James D.; Reisz, Robert R. (1 November 2016). "Aquatic adaptations in the four limbs of the snake-like reptile Tetrapodophis from the Lower Cretaceous of Brazil". Cretaceous Research. 66: 194–199. Bibcode:2016CrRes..66..194L. doi:10.1016/j.cretres.2016.06.004. ISSN   0195-6671.
  3. 1 2 Zaher, Hussam; Mohabey, Dhananjay M; Grazziotin, Felipe G; Wilson Mantilla, Jeffrey A (28 February 2023). "The skull of Sanajeh indicus , a Cretaceous snake with an upper temporal bar, and the origin of ophidian wide-gaped feeding". Zoological Journal of the Linnean Society. 197 (3): 656–697. doi:10.1093/zoolinnean/zlac001. ISSN   0024-4082.
  4. 1 2 Michael W. Caldwell; Robert R. Reisz; Randall L. Nydam; Alessandro Palci; Tiago R. Simões (2016). "Tetrapodophis amplectus (Crato Formation, Lower Cretaceous, Brazil) is not a snake". Society of Vertebrate Paleontology 76th Annual Meeting Program & Abstracts: 108. Archived from the original on 18 October 2016. Retrieved 30 October 2016.
  5. 1 2 Paparella, Ilaria; Palci, Alessandro; Nicosia, Umberto; Caldwell, Michael W. (June 2018). "A new fossil marine lizard with soft tissues from the Late Cretaceous of southern Italy". Royal Society Open Science. 5 (6): 172411. Bibcode:2018RSOS....572411P. doi:10.1098/rsos.172411. ISSN   2054-5703. PMC   6030324 . PMID   30110414.
  6. 1 2 3 4 Michael W. Caldwell; Tiago R. Simões; Alessandro Palci; Fernando F. Garberoglio; Robert R. Reisz; Michael S. Y. Lee; Randall L. Nydam (2021). "Tetrapodophis amplectus is not a snake: re-assessment of the osteology, phylogeny and functional morphology of an Early Cretaceous dolichosaurid lizard". Society of Vertebrate Paleontology, Latest Articles. 19 (13): 893–952. Bibcode:2021JSPal..19..893C. doi: 10.1080/14772019.2021.1983044 . S2CID   244414151.
  7. ↑ Yong, Ed (23 July 2015). "A Fossil Snake With Four Legs". Phenomena: Not Exactly Rocket Science. National Geographic. Retrieved 24 July 2015.
  8. 1 2 3 4 5 Christakou, Anastasia (4 August 2015). "Four-legged snake fossil sparks legal investigation". Nature. doi:10.1038/nature.2015.18116. ISSN   1476-4687.
  9. 1 2 3 Four-legged snake fossil stuns scientists—and ignites controversy (Report). 18 October 2021. doi:10.1126/science.aac8899.
  10. 1 2 "Author of 4-legged-snake paper defies Brazilian fossil laws". Herton Escobar (in Brazilian Portuguese). Retrieved 16 December 2020.
  11. ↑ Martill, David (November 2011). "Protect - and die". www.geolsoc.org.uk. The Geological Society of London. Retrieved 9 May 2024.
  12. ↑ Elbein, Asher (22 March 2021). "Decolonizing the Hunt for Dinosaurs and Other Fossils". The New York Times. ISSN   0362-4331 . Retrieved 26 June 2021.
  13. ↑ Cisneros, Juan Carlos; Raja, Nussaïbah B.; Ghilardi, Aline M.; Dunne, Emma M.; Pinheiro, Felipe L.; Regalado Fernández, Omar Rafael; Sales, Marcos A. F.; Rodríguez-de la Rosa, Rubén A.; Miranda-Martínez, Adriana Y.; González-Mora, Sergio; Bantim, Renan A. M.; de Lima, Flaviana J.; Pardo, Jason D. (2022). "Digging deeper into colonial palaeontological practices in modern day Mexico and Brazil". Royal Society Open Science. 9 (3). doi:10.1098/rsos.210898. ISSN   2054-5703. PMC   8889171 . PMID   35291323.
  14. ↑ Malleret, Constance (7 May 2024). "'Magical moment' as fire-ravaged Brazil museum receives big fossil donation". The Guardian. ISSN   0261-3077 . Retrieved 8 May 2024.
  15. ↑ Geggel, Laura (28 October 2016). "Mistaken Identity? Debate Over Ancient 4-Legged Snake Heats Up". Live Science .
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