Titanophoneus ("titanic murderer") is an extinct genus of carnivorous dinocephalian therapsid from the Middle Permian. It is classified within the family Anteosauridae. The type species is Titanophoneus potens.[1] Remains of Titanophoneus have been found at Isheevo, Russia. It was one of the last anteosaurs in Eastern Europe, as the clade was absent in the following Sundyr Assemblage, being replaced by large therocephalians.[2][3][4]
| Titanophoneus | |
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| Mounted skeleton of Titanophoneus potens | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Synapsida |
| Clade: | Therapsida |
| Suborder: | †Dinocephalia |
| Family: | †Anteosauridae |
| Subfamily: | †Anteosaurinae |
| Genus: | †Titanophoneus Efremov, 1938 |
| Type species | |
| †Titanophoneus potens Efremov, 1938 | |
| Species | |
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| Synonyms | |
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Classification
editTitanophoneus potens was named by Efremov in 1938 and was briefly described based on two skulls and associated postcrania. Despite the difference sizes of the skulls, he considered them to be members of the same species.[1]
Initially, it has been hypothesized by experts that estemmenosuchids were the most basal of the dinocephalians,[5][6] however more recent analysis have instead recovered anteosaurs as the basal dinocephalians.[7][8][1]
Kamerrer (2011) performed the first phylogenetic analysis which included all anteosaurid taxa. Along with other subsequent phylogenetic analysis of anteosaurs, this study recovered a monophyletic Anteosauridae containing two major clades, Syodontinae and Anteosaurinae: in Kammerer's analysis, the Chinese Sinophoneus is the most basal anteosaurine and the sister group of an unresolved trichotomy including T. potens, T. adamanteus, and Anteosaurus. The following cladogram is based on Kammerer (2011):[1]
Following the discovery of the Brazilian anteosaur Pampaphoneus, Cisneros et al. presented another cladogram confirming the recognition of Syodontinae and Anteosaurinae. In the Fig. 2. cladogram of the main paper (which does not include Microsyodon), T. adamanteus is recovered as the sister taxon of a clade composed of T. potens and Anteosaurus. However, in the four cladograms within the supplementary material/supporting information of this paper, (which included Microsyodon), Anteosaurus is recovered as the sister taxon of both species of Titanophoneus. These four cladograms differ only by the position of Microsyodon within the matrix.[9] The following cladograms are those from Cisneros et al. (2012); the first is from the main article, which excludes the genus Microsyodon:
| Therapsida |
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In resdescribing the Chinese anteosaur Sinophoneus, Jun Lui presented a new cladogram in which Sinophoneus is recovered as the most basal Anteosauridae and so excluded from Anteosaurinae. Here Anteosaurus is the sister-taxon of T. potens and T. adamanteus. The following cladogram is based on Jun Liu (2013):[10]
| Therapsida |
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Description
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An adult skull would have reached 80 cm (31 in) with a heavy long snout and was estimated to have measured 6 m (20 ft)in length, making it one of the largest anteosaurs.[11] T. potens can be distingusihed from most anteosaurs by the presence of an angular boss, concave dorsal snout profile, massive pachyostosis of the dorsal surface of the skull, and concave alveolar margin of the precanine region. It can be distinguished from Anteosaurus by the lack of postfrontal horns and lenticular shape of the angular boss.[1]
Paleobiology
editHabitat preference and diet
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In 2008 Mikhail Ivakhnenko analyzed a vast majority of Permian therapsid skulls, and suggested that anteosaurs, were semiaquatic piscivorous (fish-eater) synapsids, mostly similar to modern-day otters.[12] Christian F. Kammerer in 2011 questioned this proposal, given that numerous anatomical traits of anteosaurs make this lifestyle unlikely. The typical dentition of piscivorous animals include elongate, numerous, strongly recurved, and very sharp teeth in order to hold and kill fast-moving fish prey. In addition, the jaws of piscivores are commonly elongated and narrow for greater strike speed and minimal water resistance when capturing prey. In contrast, the skull morphology of most anteosaurs—specifically anteosaurids—is extremely robust with deep jaws, and the teeth are bulbous and blunt, with only the canines being significantly recurved. He also noted that anteosaurid teeth are mostly similar to that of large tyrannosaurids (postcanines robust bases, faceted surfaces, and obliquely angled serrations), whose dentition is interpreted as being specialized for bone-crunching. Accordingly, bone-crunching may also have been employed by anteosaurids, being an important component in their diet.[1]
Additionally, paleoneurology of the closely related Anteosaurus disproves the idea that these dinocephalians were sluggish, crocodilian-like predators. X-ray imaging and 3-D reconstructions showcase that Anteosaurus were fast, agile animals in spite of their great size: the inner ears were larger than those of its closest relatives and competitors, suggesting that Anteosaurus was well-suited to the role of an apex predator that could outrun both its rivals and prey alike. The area of its brain responsible for coordinating the movements of the eyes with the head was also determined to have been exceptionally large, an important feature to ensure that they could track their prey accurately.[13]
Paleoecology
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Both species of Titanophoneus were recovered in the Isheevo Assemblage Zone.[14] Contemporary dinocephalians included anteosaurs such as syodontine Syodon, the tapinocephalians include the tapinocephalid Ulemosaurus svijagensis and the deuterosaurid Deuterosaurus. Therocephalians were represented by Porosteognathus efremovi and Perplexisaurus lepusculus.[14]
The Isheevo Assemblage Zone was part Dinocephalian tetrapod fauna, dating from the Wordian to the Capitanian stage of the Middle Permian. The assemblage zone succeed the Ocher Assemblage and preceded the Sundry Assemblage.[14][15][16]Titanophoneus and other anteosaurs were absent in the following assemblage, being replaced by large basal therocephalians such as Gorynychus and Julognathus.[2][3][14]
See also
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References
edit- 1 2 3 4 5 6 Kammerer, C.F. (2011). "Systematics of the Anteosauria (Therapsida: Dinocephalia)". Journal of Systematic Palaeontology. 9 (2). doi:10.1080/14772019.2010.492645.
- 1 2 Suchkova, J. A.; Golubev, V. K. (2019). "A new primitive therocephalian (Theromorpha) from the Middle Permian of Eastern Europe". Paleontological Journal. 53 (3): 305–314. doi:10.1134/S0031030119030158.
- 1 2 Suchkova, J.A.; Golubev, V.K. (2019). "New Permian therocephalian (Therocephalia, Theromorpha) from the Sundyr Assemblage of Eastern Europe". Paleontological Journal (4): 87–92. doi:10.1134/S0031031X19040123.
- ↑ Sennikov, A. G.; Golubev, V. K. (2017). "Sequence of Permian tetrapod faunas of Eastern Europe and the Permian–Triassic ecological crisis". Paleontological Journal. 51 (6): 600–611. doi:10.1134/S0031030117060077.
- ↑ Kemp, T. S. (1982). Mammal-like Reptiles and the Origin of Mammals. New York: Academic Press. pp. 363pp.
- ↑ King, G. M. (1988). "Anomodontia". Encyclopedia of Paleoherpetology. Vol. Part 17 C. Stuttgart and New York: Gutsav Fischer Verlag.
- ↑ Rubidge, Bruce S.; Sidor, Christian A. (2001). "Evolutionary Patterns Among Permo-Triassic Therapsids". Annual Review of Ecology and Systematics. 32: 449–480.
- ↑ Bhat, M. S.; Shelton, C.; Chinsamy-Turan, A. (2021). "Bone histology of dinocephalians (Therapsida, Dinocephalia): palaeobiological and palaeoecological inferences". Papers in Palaeontology. 8. doi:10.1002/spp2.1411.
- ↑ Cisneros, J.C.; Abdala, Fernando; Atayman-Güven, S.; Rubidge, Bruce S.; Şengör, A. M. C.; Schultz, C. L. (2012). "Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 109 (5): 1584–1588. Bibcode:2012PNAS..109.1584C. doi:10.1073/pnas.1115975109. PMC 3277192. PMID 22307615.
- ↑ Liu, J. (2013). "Osteology, Ontogeny, and Phylogenetic Position of Sinophoneus yumenensis (Therapsida, Dinocephalia) from the Middle Permian Dashankou Fauna of China". Journal of Vertebrate Paleontology. 33 (6): 1394–1407. Bibcode:2013JVPal..33.1394L. doi:10.1080/02724634.2013.781505. S2CID 85577626.
- ↑ Cisneros, J.C.; Abdala, F.; Atayman-Güven, S.; Rubidge, B.S.; Şengör, A.M.C.; Schultz, C.L. (2012). "Carnivorous dinocephalian from the Middle Permian of Brazil and tetrapod dispersal in Pangaea" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 109 (5): 1584–1588. Bibcode:2012PNAS..109.1584C. doi:10.1073/pnas.1115975109. PMC 3277192. PMID 22307615.
- ↑ Ivakhnenko, M. F. (2008). "Cranial morphology and evolution of Permian Dinomorpha (Eotherapsida) of eastern Europe". Paleontological Journal. 42 (9): 859−995. Bibcode:2008PalJ...42..859I. doi:10.1134/S0031030108090013. S2CID 85114195.
- ↑ Benoit, J.; Kruger, A.; Jirah, S.; Fernandez, V.; Rubidge, Bruce S. (2021). "Palaeoneurology and palaeobiology of the dinocephalian therapsid Anteosaurus magnificus" (PDF). Acta Palaeontologica Polonica. 66. doi:10.4202/app.00800.2020.
- 1 2 3 4 Sennikov, A. G.; Golubev, V. K. (2017). "Sequence of Permian tetrapod faunas of Eastern Europe and the Permian–Triassic ecological crisis". Paleontological Journal. 51 (6): 600–611. doi:10.1134/S0031030117060077.
- ↑ Golubev, Valeriy K.; Bulanov, V. V. (2018). "Amphibians of the Permian Sundyr Tetrapod Assemblage of Eastern Europe". Paleontological Journal. 52 (6): 639–652. doi:10.1134/S0031030118060059.
- ↑ Uliakhin, A. V.; Golubev, V. K. (2024). "Ancient Species of the Genus Dvinosaurus (Temnospondyli, Dvinosauria) from the Permian Sundyr Tetrapod Assemblage of Eastern Europe". Paleontological Journal. 58 (2): 204–225. doi:10.1134/S0031030123600336.
- Vickers-Rich, Patricia; Thomas H. Rich (1993). The Great Russian Dinosaurs. Guntar Graphics. p. 36.