# Uluciala

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***Uluciala*** (lit. 'owl wing') is an [extinct](/source/Extinct) genus of [decabrachian](/source/Decabrachia) ([squid](/source/Squid) relative) [cephalopod](/source/Cephalopod) mollusc known from [Late Cretaceous](/source/Late_Cretaceous) [Pierre Shale](/source/Pierre_Shale) and [Fox Hill Formation](/source/Fox_Hill_Formation) of [South Dakota](/source/South_Dakota), United States. The genus contains a [single species](/source/Monotypic_taxon), ***Uluciala rotundata***, named based on two lower [beaks](/source/Cephalopod_beak). These show a morphology intermediate between [Sepiida](/source/Sepiida) ([cuttlefish](/source/Cuttlefish)) and [Sepiolida](/source/Sepiolida) (bobtail squid), indicating *Uluciala* is closely related to these clades. These remains were discovered using "digital fossil-mining" techniques that incorporated a zero-shot learning AI model, representing the first application of this technology in both paleontological research and full-color [tomographic data](/source/Tomography).

## Discovery and naming

The *Uluciala* fossil material, comprising two lower [beaks](/source/Cephalopod_beak), was preserved in [carbonate](/source/Carbonate) [concretions](/source/Concretion) collected in outcrops representing deposits of the [Western Interior Seaway](/source/Western_Interior_Seaway) in [South Dakota](/source/South_Dakota), United States. One beak-bearing concretion was found in the upper part of the [Pierre Shale](/source/Pierre_Shale) ([AMNH](/source/AMNH) loc. 3274) in [Meade County](/source/Meade_County,_South_Dakota). This locality has been assigned to the [*Baculites compressus*/*cuneatus*](/source/Baculites) ammonite Zone, dating it to the late [Campanian](/source/Campanian) age (~) via [biostratigraphy](/source/Biostratigraphy). The second concretion was found in the Timber Lake Member of the [Fox Hill Formation](/source/Fox_Hill_Formation) (AMNH loc. 3272) in [Dewey County](/source/Dewey_County,_South_Dakota). This locality has been assigned to the *[Hoploscaphites nebrascensis](/source/Hoploscaphites)* ammonite Zone, dating it to the late Maastrichtian (~).[1]

To study the contents of these carbonate concretions, researchers began by cutting them into appropriately-sized blocks and conducting grinding [tomography](/source/Tomography). This is a destructive imaging technique in which the block is slowly ground down in slices (increments of 50 μm (0.050 mm) or 25 μm (0.025 mm) used for these specimens), with high-resolution photographs taken of the block after each 'slice'. The images can then be digitally stacked, allowing the full structure of the specimen(s) to be viewed at any layer in [cross-section](/source/Multiview_orthographic_projection#Section).[2] To allow efficient [segmentation](/source/Image_segmentation) of the sectional data, the researchers applied DEVA (decoupled video segmentation approach) technology, an [artificial intelligence](/source/Artificial_intelligence)-powered tool developed for recognizing and tracking objects between video frames.[3] For this study, a [zero-shot learning](/source/Zero-shot_learning) AI was used, which was pre-trained via DEVA on generalized mask data, but not on tomography- or fossil-specific data. As such, it can segment any object in the data, even if it has not been trained on it. Once the tomography slices have been segmented, a 3D model can be produced, allowing for full visualization of objects previously embedded in stone. The research by Sugiura and colleagues on these squid beaks is the first time zero-shot learning AI and DEVA technology have been applied to either colored tomographic data or paleontology research.[1]

In 2026, Kanta Sugiura and colleagues [described](/source/Species_description) *Uluciala rotundata* as a new genus and species of [cuttlefish](/source/Cuttlefish)-like [decabrachian](/source/Decabrachia) based on the digital models extracted from the tomography data. Since the original carbonate concretions—and the fossils contained therein—were destroyed to produce this data, the researchers treated these models as the known 'specimens', referred to as NMNS_DS00254_0k5cvkE.stl and NMNS_DS00285_ma2jp6.stl. These files are deposited in both the [National Museum of Nature and Science](/source/National_Museum_of_Nature_and_Science) (NMNS) in [Tokyo](/source/Tokyo), Japan, and the [American Museum of Natural History](/source/American_Museum_of_Natural_History) (AMNH) in [New York](/source/New_York_(state)), United States. The [generic name](/source/Genus), *Uluciala*, combines the [Latin](/source/Latin) words *ulucus*, meaning 'owl', and *ala*, meaning 'wing', in reference to the superficial similarity in form of the animal's beak with the wings of an owl. The [specific name](/source/Specific_name_(zoology)), *rotundata*, is a Latin word meaning 'rounded', alluding to the shape of the [rostrum](/source/Rostrum_(anatomy)#Invertebrates).[1]

## Description and classification

*Uluciala* is recognized as a 'sepioid', which is the name applied to the group including the clades [Sepiida](/source/Sepiida) ([cuttlefish](/source/Cuttlefish)) and [Sepiolida](/source/Sepiolida) (bobtail squid). As such, it is more closely related to these taxa than to [nautiluses](/source/Nautilus), [octopuses](/source/Octopus), and other [squid](/source/Squid). Furthermore, *Uluciala* is the oldest known member of this lineage. The rostral tip of th beak of *Uluciala* forms a large, rounded hook.[1]

## References

1. Sugiura, Kanta; Ikegami, Shin; Takeda, Yusuke; Mutterlose, Jörg; Derin, Mehmet Oguz; Kubota, Aya; Nishida, Harufumi; Tainaka, Kazuki; Harada, Takahiro; Landman, Neil H.; Iba, Yasuhiro (2026-01-16). "The oldest sepioid cephalopod from the Cretaceous discovered by digital fossil-mining with zero-shot learning AI". *[Communications Biology](/source/Communications_Biology)*. [doi:10.1038/s42003-026-09519-9](https://doi.org/10.1038/s42003-026-09519-9). [ISSN 2399-3642](https://www.worldcat.org/issn/2399-3642)

1. Ikegami, Shin; Takeda, Yusuke; Mutterlose, Jörg; Iba, Yasuhiro (June 26, 2025). "Origin and radiation of squids revealed by digital fossil-mining". *[Science](/source/Science_(journal))*. **388** (6754): 1406–1409. [doi:10.1126/science.adu6248](https://doi.org/10.1126/science.adu6248). [ISSN 0036-8075](https://www.worldcat.org/issn/0036-8075)

1. Cheng, Ho Kei; Wug Oh, Seoung; Price, Brian; Schwing, Alexander; Lee, Joon-Young (October 2023). [*Tracking anything with decoupled video segmentation*](https://helios2.mi.parisdescartes.fr/~lomn/Cours/CV/SeqVideo/CollaborativeWork/SOTA/Cheng_Tracking_Anything_with_Decoupled_Video_Segmentation_ICCV_2023_paper.pdf). 2023 IEEE/CVF International Conference on Computer Vision. IEEE. pp. 1316–1326. [doi:10.1109/ICCV51070.2023.00127](https://doi.org/10.1109/ICCV51070.2023.00127). ISBN 979-8-3503-0718-4.

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Adapted from the Wikipedia article [Uluciala](https://en.wikipedia.org/wiki/Uluciala) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Uluciala?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.