Minimocursor Explained

Minimocursor (meaning "smallest runner") is a genus of basal neornithischian dinosaur from the Late Jurassic Phu Kradung Formation of Thailand. The type species is Minimocursor phunoiensis.[1]

Discovery and naming

The holotype specimen, PRC 150, was excavated in 2012 and prepared for the next five years. It consists of a postcranial specimen that is more than 50% complete. Other referred specimens include an isolated dentary briefly described in 2014 and pes material.[2] Several more specimens remain unprepared as of 2023.

These bones were considered to represent a new genus and species, Minimocursor phunoiensis, in 2023. The generic name, "Minimocursor", combines the Latin words "minimus", meaning "the smallest", in reference to the holotype's small size, and "cursor", meaning "runner". The specific name, "phunoiensis", refers to the excavation site, Phu Noi.

Description

The not-fully-grown holotype has been estimated as 0.6m (02feet) long, similar to the size of Agilisaurus. Larger remains hint that the fully-grown animal would have been 2m (07feet) long.

Phylogeny

Manitkoon et al. (2023) added Minimocursor to a phylogenetic analysis, adding the holotype, pes, and dentary as separate operational taxonomic units (OTUs). All three claded together at the base of the Neornithischia, outside Thescelosauridae and Cerapoda, making it the first basal neornithischian known from Southeast Asia. Their cladogram is shown below:

Palaeoenvironment

The Phu Kradung Formation preserves a diverse assemblage of animals. Minimocursor would have lived alongside several fish and turtles, an indeterminate pterosaur, an indeterminate stegosaur, an indeterminate metriacanthosaurid, an indeterminate mamenchisaurid, and the thalattosuchian Indosinosuchus.[3] [4]

Notes and References

  1. Manitkoon. Sita. Deesri. Uthumporn. Khalloufi. Bouziane. Nonsrirach. Thanit. Suteethorn. Varavudh. Chanthasit. Phornphen. Boonla. Wansiri. Buffetaut. Eric. A New Basal Neornithischian Dinosaur from the Phu Kradung Formation (Upper Jurassic) of Northeastern Thailand. 2023. Diversity. 15. 7. 851. 10.3390/d15070851. free .
  2. Buffetaut . Eric . Suteethorn . Suravech . Suteethorn . Varavudh . Deesri . Uthumporn . Tong . Haiyan . 2014 . Preliminary note on a small ornithopod dinosaur from the Phu Kradung Formation (terminal Jurassic – basal Cretaceous) of Phu Noi, north-eastern Thailand . Journal of Science and Technology, Mahasarakham University . 33 . 4 . 344–347.
  3. Martin. Jeremy E. . Suteethorn . S. . Lauprasert . K. . February 2019 . A new freshwater teleosaurid from the Jurassic of northeastern Thailand . Journal of Vertebrate Paleontology . 64 . 2 . 239–260 . en . 10.1080/02724634.2018.1549059. 91988192 .
  4. Moore . Andrew J. . Barrett . Paul M. . Upchurch . Paul . Liao . Chun-Chi . Ye . Yong . Hao . Baoqiao . Xu . 2023 . Re-assessment of the Late Jurassic eusauropod Mamenchisaurus sinocanadorum Russell and Zheng, 1993, and the evolution of exceptionally long necks in mamenchisaurids . Journal of Systematic Palaeontology . 21 . 1 . 10.1080/14772019.2023.2171818. 257573094 .