Alickmeron

Alickmeron Temporal range: Late Triassic, 228  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Holotype femora
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	† Pterosauromorpha
Family:	† Lagerpetidae
Genus:	† Alickmeron Sen & Ray, 2025
Species:	†A. maleriensis
Binomial name
†Alickmeron maleriensis

Alickmeron ("Alick's femur") is an extinct genus of lagerpetid pterosauromorphs from the Late Triassic (Norian) Upper Maleri Formation of India. The type species is Alickmeron maleriensis.

Discovery and naming

In 1987, Sankar Chatterjee named Walkeria (later renamed Alwalkeria ) ^[1] maleriensis as a new podokesaurid theropod dinosaur based on a partial skull, 28 incomplete vertebrae from all parts of the spinal column, a proximal left femur and distal right femur, and an astragalus (ankle bone). The bones were collected in the Godavari Valley locality from the Upper Maleri Formation of Andhra Pradesh, India by S. Chatterjee in 1974. The specimen is housed in the collection of the Indian Statistical Institute, in Kolkata, India. The generic name honors British paleontologist Alick Walker, and the specific name, maleriensis, references the Upper Maleri Formation, in southern India, where its fossils were found. ^[2]

Later research indicated that the originally-proposed hypodigm was chimeric, with the skull bones belonging to a member of the Crocodylomorpha. Lecuona and colleagues (2016) claimed the distal femur was more consistent with the morphology of pseudosuchians, leading them to identify this bone fragment as an indeterminate representative of that clade. The vertebrae further lack anatomical features allowing for a precise identification, dinosaur, pseudosuchian, or otherwise. ^[3] .

In 2025, Sen & Ray affirmed the chimeric status of the specimen and claimed the femora could be described as a new genus of lagerpetid pterosauromorphs, which they named Alickmeron, honoring Walker. The astragalus remains the only bone from the specimen that they consider dinosaurian, finding it to be an indeterminate saurischian morphologically similar to an unnamed Argentinian herrerasaurid. ^[4]

Classification

Speculative life restoration of the lagerpetid Kongonaphon

Sen & Ray (2025) performed two phylogenetic analyses to test the position of Alickmeron, the astragalus referred to Alwalkeria, and a second, unnamed dinosaur from the Upper Maleri Formation. Using the dataset of Mestriner et al. (2023), ^[5] they recovered Alickmeron as a member of the Lagerpetidae, as the sister taxon to a clade formed by Venetoraptor and Kongonaphon . A cladogram adapted from this analysis is shown below: ^[4]

Lagerpetidae	Ixalerpeton Lagerpeton Dromomeron gregorii Dromomeron gigas Dromomeron romeri Alickmeron Venetoraptor Kongonaphon

Paleoecology

The Maleri Formation has been interpreted as being the site of an ancient lake or river. Material of the sauropodomorphs Jaklapallisaurus and Nambalia and the herrerasaurian Maleriraptor have been found in the Upper Maleri Formation, as well as intermediate prosauropod remains. ^[6]

References

1. Chatterjee, S. & Creisler, B.S. 1994. Alwalkeria (Theropoda) and Morturneria (Plesiosauria), new names for preoccupied Walkeria Chatterjee, 1987, and Turneria Chatterjee and Small, 1989. Journal of Vertebrate Paleontology 14(1): 142.
2. Chatterjee, S. 1987. A new theropod dinosaur from India with remarks on the Gondwana-Laurasia connection in the Late Cretaceous. In: McKenzie, G.D. (Ed.). Gondwana Six: Stratigraphy, Sedimentology, and Paleontology. Geophysical Monograph 41. Washington, D.C.: American Geophysical Union. Pp. 183–189.
3. Lecuona, Agustina; Ezcurra, Martín D.; Irmis, Randall B. (2016-10-03). Angielczyk, Kenneth (ed.). "Revision of the early crocodylomorph Trialestes romeri (Archosauria, Suchia) from the lower Upper Triassic Ischigualasto Formation of Argentina: one of the oldest‐known crocodylomorphs". Papers in Palaeontology. 2 (4): 585–622. doi:10.1002/spp2.1056. hdl: 11336/66393 . ISSN   2056-2799.
4. Sen, Sulagna; Ray, Sanghamitra (2025). "Taxonomic reassessment of archosaurs with dinosaurian affinities from the lower fauna of the Upper Triassic Maleri Formation of India and their significance". Journal of Vertebrate Paleontology . e2546434. doi:10.1080/02724634.2025.2546434.
5. Mestriner, G.; Marsola, J. C. A.; Nesbitt, S. J.; Da-Rosa, Á. A. S.; Langer, M. (2023). "Anatomy and phylogenetic affinities of a new silesaurid assemblage from the Carnian beds of south Brazil". Journal of Vertebrate Paleontology. 43 (1). e2232426. Bibcode:2023JVPal..43E2426M. doi:10.1080/02724634.2023.2232426. S2CID   261157405.
6. Ezcurra, Martín D.; Garcia, Maurício Silva; Novas, Fernando E.; Müller, Rodrigo Temp; Agnolín, Federico L.; Chatterjee, Sankar (2025-05-07). "A new herrerasaurian dinosaur from the Upper Triassic Upper Maleri Formation of south-central India". Royal Society Open Science . 12 (5). doi: 10.1098/rsos.250081 . ISSN   2054-5703. PMC   12077243 .