Catonyx

Catonyx; Temporal range: Early Pliocene-Early Holocene (Montehermosan-Lujanian); ~2.5–0.010 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Replica of a Catonyx skull at the Museo delle Scienze
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Pilosa
Family:	† Scelidotheriidae
Genus:	† Catonyx ; Ameghino, 1891
Species
	C. cuvieriLund, 1839; C. chiliensisLydekker, 1886; C. tarijensisGervais and Ameghino, 1880;

Last updated December 03, 2024

Catonyx is an extinct genus of ground sloth of the family Scelidotheriidae, endemic to South America during the Pliocene and Pleistocene epochs.^[1] It lived from 2.5 Ma to about 10,000 years ago, existing for approximately 2.49 million years.^[2] The most recent date obtained is about 9600 B.P.^[3]^[4]

Description

This animal, like many other terrestrial sloths, was of conspicuous size and mighty build. It had to reach and exceed 4 meters in length, and the skull alone was at least 50 centimeters long. Its weight has been estimated at over 1500 kg. ^[5] The snout of Catonyx was elongated, although not as in some similar forms (e.g., Scelidotherium ). Unlike the latter, Catonyx possessed shorter premaxillae that formed a triangular (and not rectangular like Scelidotherium ) snout tip, a pronounced rostrum bulge, a palate equipped with a median groove, and larger teeth. In addition, the mandibular symphysis was elongated and elevated, and the posterior lobe of the lower fourth molar was more curved than that of Scelidotherium. Like all terrestrial sloths, Scelidotherium possessed strong-boned limbs and large claws.

Taxonomy

At a cave in Lagoa Santa, Brazil, Peter Wilhelm Lund and his crew members collected the fragmentary fossils of a fossil sloth that Wilhelm named Megalonyx cuvieri in 1838. Catonyx, the genus name, was made by Ameghino in 1891. It was assigned to Scelidotheriinae by Gaudin in 1995.^[6] Scelidotheriinae was elevated back to family status by Presslee et al. in 2019.^[7]

The very first fossils of this animal were found in Upper Pleistocene strata of Brazil and were described by Lund in 1839, but for a long time there was considerable systematic confusion: the remains were gradually attributed to the genera Scelidotherium and Scelidodon . Only recently have revisions based on clear morphological anatomy been proposed, according to which the genera Scelidotherium and Catonyx are two valid taxa, while Scelidodon may or may not be a valid genus. Catonyx, in any case, is a member of the Scelidotheriidae, a group of terrestrial sloths known from the Miocene, Pliocene, and Pleistocene and characterized by an elongated snout; scelidotheres themselves part are usually placed as a subfamily of the Mylodontidae, although they are sometimes considered a separate family, Scelidotheriidae.^[7]

The type species of Catonyx is Catonyx cuvieri , named in 1839 by Peter Wilhelm Lund. C. cuvieri has been found in Brazil and Uruguay, and dates to the Late Pleistocene and likely the Early Holocene.^[8] Other species attributed to this genus but are sometimes considered to belong to a separate genus, Scelidodon, are C. tarijensis and C. chiliense, found in Chile, Argentina, Uruguay, Bolivia, and Ecuador.

Below is a phylogenetic tree of the Scelidotheriinae, based on the work of Nieto and colleagues (2020), showing the position of Catonyx.^[9]

Scelidotheriinae

Sibyllotherium guenguelianum

Neonematherium flabellatum

Scelidotherium

Proscelidodon gracillimus

Proscelidodon patrius

	Proscelidodon rothi

	Valgipes bucklandi

	Catonyx cuvieri

	Catonyx tarijensis

	Catonyx chiliense

Palaeobiology

The cranial anatomy of the species C. tarijensis indicates it may have been a browser which used its strong lips to grab vegetation,^[10] and Santos Pereira et al. (2013) tentatively suggested browsing habits for C. cuvieri.^[11] Isotopic analysis of Smilodon populator remains from Brazil indicates that Catonyx was one of its main prey items.^[12]

Fossil distribution

Fossils of Catonyx have been uncovered in Brazil, the San José Formation of Uruguay, the Tezanos Pinto Formation of Argentina,^[13] and the Tarija Valley of Bolivia.^[10]

Paleoecology

In the Brazilian Intertropical Region in eastern Brazil, Catonyx was a browser in arboreal savannahs and forested grasslands. Large, mesoherbivorous mammals in the BIR were widespread and diverse, including the cow-like toxodontids Toxodon platensis and Piauhytherium , the macraucheniid litoptern Xenorhinotherium and equids such as Hippidion principale and Equus neogaeus. Toxodontids were large mixed feeders as well and lived in forested areas, while the equids were nearly entirely grazers. Other xenarthran fossils are present in the area as well from several different families, like the giant megatheriid ground sloth Eremotherium, the fellow scelidotheriid Valgipes , the mylodontids Glossotherium , Ocnotherium , and Mylodonopsis . Smaller ground sloths such as the megalonychids Ahytherium and Australonyx and the nothrotheriid Nothrotherium have also been found in the area. Eremotherium was a generalist, while Nothrotherium was a specialist for trees in low density forests, and Valgipes was an intermediate of the two that lived in arboreal savannahs. Other glyptodonts and cingulates like the grazing glyptodonts Glyptotherium and Panochthus and the omnivorous pampatheres Pampatherium and Holmesina were present in the open grasslands. A proboscidean species has also been found in the BIR, Notiomastodon platensis, which was also present and was a mixed grazer on the open grasslands. Carnivores included some of the largest known mammalian land carnivores, like the giant felid Smilodon populator and the bear Arctotherium wingei.^[14]^[15] Several extant taxa are also known from the BIR, like guanacos, giant anteaters, collared peccaries, and striped hog-nosed skunks.^[16] Two crab-eating types of extant mammals are also known from the BIR, the crab-eating raccoon and the crab-eating fox, indicating that crabs were also present in the region.^[16] The environment of the BIR is unclear, as there were both several species that were grazers, but the precede of the arboreal fossil monkeys Protopithecus and Caipora in the area causes confusion over the area's paleoenvironment. Most of Brazil was thought to have been covered in open tropical cerrado vegetation during the Late Pleistocene, but if Protopithecus and Caipora were arboreal, their presence suggests that the region may have supported a dense closed forest during the Late Pleistocene.^[16]^[17] It is possible that the region alternated between dry open savannah and closed wet forest throughout the climate change of the Late Pleistocene.^[18]

Related Research Articles

Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another family of extinct ground sloths, Scelidotheriidae, as well as to the extant arboreal two-toed sloths, family Choloepodidae; together these make up the superfamily Mylodontoidea. Phylogenetic analyses based on morphology uncovered the relationship between Mylodontidae and Scelidotheriidae; in fact, the latter was for a time considered a subfamily of mylodontids. However, molecular sequence comparisons were needed for the correct placement of Choloepodidae. These studies have been carried out using mitochondrial DNA sequences as well as with collagen amino acid sequences. The latter results indicate that Choloepodidae is closer to Mylodontidae than Scelidotheriidae is. The only other living sloth family, Bradypodidae, belongs to a different sloth radiation, Megatherioidea.

Scelidotheriidae is a family of extinct ground sloths within the order Pilosa, suborder Folivora and superfamily Mylodontoidea, related to the other extinct mylodontoid family, Mylodontidae, as well as to the living two-toed sloth family Choloepodidae. The only other extant family of the suborder Folivora is the distantly related Bradypodidae. Erected as the family Scelidotheriidae by Ameghino in 1889, the taxon was demoted to a subfamily of Mylodontidae by Gaudin in 1995. However, recent collagen sequence data indicates the group is less closely related to Mylodon and Lestodon than Choloepus is, and thus it has been elevated back to full family status by Presslee et al. (2019).

Scelidotherium is an extinct genus of ground sloth of the family Scelidotheriidae, endemic to South America during the Late Pleistocene epoch. It lived from 780,000 to 11,000 years ago, existing for approximately 0.67 million years.

Glossotherium is an extinct genus of large mylodontid ground sloths of the subfamily Mylodontinae. It represents one of the best-known members of the family, along with Mylodon and Paramylodon. Reconstructed animals were between 3 and 4 metres long and possibly weighed up to 1,002.6–1,500 kg. The majority of finds of Glossotherium date from the Middle and Upper Pleistocene, around 300,000 to 10,000 years ago, with a few dating older, as far back Pliocene, about 3.3-3 million years ago. The range included large parts of South America, east of the Andes roughly from latitude 20 to 40 degrees south, leaving out the Amazon Basin in the north. In western South America, finds are also documented north of the equator. The animals largely inhabited the open landscapes of the Pampas and northern savanna regions.

Chubutherium is an extinct genus of ground sloth from the Late Oligocene and Early Miocene of Chubut Province, Argentina.

Eremotherium is an extinct genus of giant ground sloth in the family Megatheriidae. Eremotherium lived in southern North America, Central America, and northern South America from the Pliocene, around 5.3 million years ago, to the end of the Late Pleistocene, around 10,000 years ago. Eremotherium was one of the largest ground sloths, with a body size comparable to elephants, weighing around 4–6.5 tonnes and measuring about 6 metres (20 ft) long, slightly larger than its close relative Megatherium.

Lestodon is an extinct genus of giant ground sloth native to South America during the Pleistocene epoch. Its fossil remains have been primarily been found in the Pampas and adjacent regions. The largest member of the family Mylodontidae, It is estimated to have weighed 4,100 kilograms. It was a herbivore and primarily fed on the grasses and low-growing plants.

Mylodontinae is an extinct subfamily of ground sloths that lived from the Early Miocene to the Early Holocene epochs.

<i>Ahytherium</i> Extinct genus of sloths

Ahytherium is an extinct genus of megalonychid sloth that lived during the Pleistocene of what is now Brazil. It contains a single species, A. aureum.

Nematherium is an extinct genus of ground sloth belonging to Mylodontoidea, it is either considered to be a member of Mylodontidae or Scelidotheriidae. It lived during the Middle Miocene epoch (Santacrucian). Fossils have been found in the Cura-Mallín Formation of Chile and the Santa Cruz and Sarmiento Formations of Argentina.

Piauhytherium is an extinct genus of herbivorous notoungulate mammal of the family Toxodontidae. It lived during the Late Pleistocene; fossils have been found in Brazil. The only known species is Piauhytherium capivarae.

Australonyx is an extinct genus of ground sloths, endemic to South America during the Late Pleistocene. It was found in Brazil.

Valgipes is an extinct genus of scelidotheriid ground sloth, endemic to intertropical Brazil and Uruguay during the Late Pleistocene. Thought to have been a forest-dwelling browser, Valgipes is a monotypic genus with a complex and long taxonomic history, and is a close relative of Catonyx and Proscelidodon.

<i>Proscelidodon</i> Extinct genus of ground sloths

Proscelidodon is an extinct genus of ground sloths in the family Scelidotheriidae. It lived during the Miocene and Pliocene of what is now Argentina and Bolivia. The genus was described in 1935.

Archaeomylodon is an extinct genus of mylodontine ground sloths that lived during the Middle Pleistocene of what is now Argentina. It is known so far only from a single skull, which in its dimensions corresponds to those of the giant Lestodon. However, the skull differs from this one by its narrower and higher snout. In addition, the anterior canine teeth, which are usually large in many mylodonts, are greatly reduced. The find comes from the Pampa region of South America and was deposited in about 700,000 years old sediments.

Urumacotherium is an extinct genus of ground sloths of the family Mylodontidae. It lived from the Middle Miocene to the Early Pliocene of what is now Brazil, Peru and Venezuela.

Simomylodon is an extinct genus of ground sloths from the family Mylodontidae. It lived from the Late Miocene to the Middle Pliocene of what is now Bolivia and Argentina, 5.3 to 2.8 million years ago. The most important find material comes from the central Altiplano in Bolivia and includes several skulls and dentition remains. Thus, the so far documented body skeleton is the best known and most significant of a Miocene representative of the Mylodontidae. On the basis of the remains, it can be concluded that it is a rather small member of the Mylodontidae. The construction of the limbs supports ground-dwelling locomotion, but this does not exclude occasional digging or climbing. The type and only known species is Simomylodon uccasamamensis.

Neonematherium is an extinct genus of scelidotheriid ground sloths that lived in Argentina, Chile, and Colombia during the Early to Late Miocene. Fossils have been found in the Honda Group of Colombia, and the Río Frías Formation of Chile.

Mylodonopsis is an extinct genus of ground sloth, containing a single species, Mylodonopsis ibseni from the Late Pleistocene of Brazil. It is a member of the family Mylodontidae. Although only known from fragmentary fossil remains, it has been proposed to be closely related to Mylodon.

The Dolores Formation is a Lujanian geologic formation in Uruguay.

References

↑ McDonald, H. G.; Perea, D. (2002). "The large scelidothere Catonyx tarijensis (Xenarthra, Mylodontidae) from the Pleistocene of Uruguay". Journal of Vertebrate Paleontology. 22 (3): 677. doi:10.1671/0272-4634(2002)022[0677:TLSCTX]2.0.CO;2. JSTOR 4524258. S2CID 86021240.
↑ PaleoBiology Database: Catonyx, basic info
↑ Turvey, Sam (2009). Holocene extinctions. Oxford University Press. pp. 20–33, 42–50, 352. ISBN 978-0-19-953509-5.
↑ Fiedal, Stuart (2009). "Sudden Deaths: The Chronology of Terminal Pleistocene Megafaunal Extinction". In Haynes, Gary (ed.). American Megafaunal Extinctions at the End of the Pleistocene. Vertebrate Paleobiology and Paleoanthropology. Springer. pp. 21–37. doi:10.1007/978-1-4020-8793-6_2. ISBN 978-1-4020-8792-9.
↑ Toledo, N.; Bargo, M. S.; Vizcaíno, S. F.; De Iuliis, G.; Pujos, F. (2017). "Evolution of body size in anteaters and sloths (Xenarthra, Pilosa): phylogeny, metabolism, diet and substrate preferences". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 106 (4): 289–301. Bibcode:2015EESTR.106..289T. doi: 10.1017/S1755691016000177 . hdl: 11336/56403 . S2CID 90400372.
↑ Gaudin, T. J. (1995). "The ear region of edentates and the phylogeny of the Tardigrada (Mammalia, Xenarthra)". Journal of Vertebrate Paleontology. 15 (3): 672–705. Bibcode:1995JVPal..15..672G. doi:10.1080/02724634.1995.10011255. JSTOR 4523658.
1 2 Presslee, S.; Slater, G. J.; Pujos, F.; Forasiepi, A. M.; Fischer, R.; Molloy, K.; Mackie, M.; Olsen, J. V.; Kramarz, A.; Taglioretti, M.; Scaglia, F.; Lezcano, M.; Lanata, J. L.; Southon, J.; Feranec, R.; Bloch, J.; Hajduk, A.; Martin, F. M.; Gismondi, R. S.; Reguero, M.; de Muizon, C.; Greenwood, A.; Chait, B. T.; Penkman, K.; Collins, M.; MacPhee, R.D.E. (2019). "Palaeoproteomics resolves sloth relationships" (PDF). Nature Ecology & Evolution. 3 (7): 1121–1130. Bibcode:2019NatEE...3.1121P. doi:10.1038/s41559-019-0909-z. PMID 31171860. S2CID 174813630.
↑ Corona, Andrea; Perea, Daniel; McDonald, H. Gregory (2013). "Catonyx cuvieri (Xenarthra, Mylodontidae, Scelidotheriinae) from the late Pleistocene of Uruguay, with comments regarding the systematics of the subfamily". Journal of Vertebrate Paleontology. 33 (5): 1214–1225. Bibcode:2013JVPal..33.1214C. doi:10.1080/02724634.2013.764311. ISSN 0272-4634. S2CID 84078331.
↑ Nieto, Gastón L.; Haro, J. Augusto; McDonald, H. Gregory; Miño-Boilini, Ángel R.; Tauber, Adan A.; Krapovickas, Jerónimo M.; Fabianelli, Maximiliano N.; Rosas, Federico M. (2021-06-01). "The Skeleton of the Manus of Scelidotherium (Xenarthra, Mylodontidae) Specimens from the Pleistocene of the Province of Córdoba, Argentina, and its Systematic Implications". Journal of Mammalian Evolution. 28 (2): 221–243. doi:10.1007/s10914-020-09520-x. ISSN 1573-7055. S2CID 226319627.
1 2 Boscaini, Alberto; Iurino, Dawid A.; Mamani Quispe, Bernardino; Andrade Flores, Rubén; Sardella, Raffaele; Pujos, François; Gaudin, Timothy J. (2020). "Cranial Anatomy and Paleoneurology of the Extinct Sloth Catonyx tarijensis (Xenarthra, Mylodontidae) From the Late Pleistocene of Oruro, Southwestern Bolivia". Frontiers in Ecology and Evolution. 8. doi: 10.3389/fevo.2020.00069 . hdl: 2434/959871 . ISSN 2296-701X.
↑ dos Santos Pereira, I. C.; et al. (2013). "Record of the giant sloth Valgipes bucklandi (Lund, 1839) (Tardigrada, Scelidotheriinae) in Rio Grande do Norte state, Brazil, with notes on taphonomy and paleoecology". Journal of South American Earth Sciences. 43: 42–45. Bibcode:2013JSAES..43...42P. doi:10.1016/j.jsames.2012.11.004.
↑ Dantas, Mário André Trindade; Cherkinsky, Alexander; Lessa, Carlos Micael Bonfim; Santos, Luciano Vilaboim; Cozzuol, Mario Alberto; Omena, Érica Cavalcante; Silva, Jorge Luiz Lopes; Sial, Alcides Nóbrega; Bocherens, Hervé (2020-07-14). "Isotopic paleoecology (δ13C, δ18O) of a late Pleistocene vertebrate community from the Brazilian Intertropical Region". Revista Brasileira de Paleontologia. 23 (2): 138–152. doi: 10.4072/rbp.2020.2.05 . ISSN 2236-1715.
↑ "Fossilworks: Catonyx".
↑ Keeley, J. E., & Rundel, P. W. (2003). Evolution of CAM and C4 carbon-concentrating mechanisms. International journal of plant sciences, 164(S3), S55-S77.
↑ Omena, Érica Cavalcante; Silva, Jorge Luiz Lopes da; Sial, Alcides Nóbrega; Cherkinsky, Alexander; Dantas, Mário André Trindade (2021-10-03). "Late Pleistocene meso-megaherbivores from Brazilian Intertropical Region: isotopic diet (δ13C), niche differentiation, guilds and paleoenvironmental reconstruction (δ13C, δ18O)". Historical Biology. 33 (10): 2299–2304. Bibcode:2021HBio...33.2299O. doi:10.1080/08912963.2020.1789977. ISSN 0891-2963. S2CID 225543776.
1 2 3 Cartelle, Castor; Hartwig, W. C. (1996). "A new extinct primate among the Pleistocene megafauna of Bahia, Brazil". Proceedings of the National Academy of Sciences. 93 (13): 6405–6409.
↑ Eisenberg, John F.; Redford, Kent H. (1989). Mammals of the Neotropics, Volume 3: Ecuador, Bolivia, Brazil. University of Chicago Press. p. 247. ISBN 978-0-226-19542-1.
↑ Halenar, Lauren B. (December 2011). "Reconstructing the Locomotor Repertoire of Protopithecus brasiliensis". The Anatomical Record. 294 (12): 2048–2063.