This paper is a rather belated follow-up to Foster and Wedel (2014), “Haplocanthosaurus (Saurischia: Sauropoda) from the lower Morrison Formation (Upper Jurassic) near Snowmass, Colorado”. For more about that paper, see this page.
Citation and link to the paper
Wedel, Mathew; Atterholt, Jessie; Dooley, Jr., Alton C.; Farooq, Saad; Macalino, Jeff; Nalley, Thierra K.; Wisser, Gary; and Yasmer, John. 2021. Expanded neural canals in the caudal vertebrae of a specimen of Haplocanthosaurus. Academia Letters, Article 911, 10pp. DOI: 10.20935/AL911
SV-POW! posts
My pre-publication posts on Haplocanthosaurus in general, and on the Snowmass Haplocanthosaurus project in particular
- February 11, 2009: A new paper, and a pneumatic hiatus at last
- August 22, 2012: Haplocanthosaurus sacral 4 remix
- December 16, 2014: My new paper on Haplocanthosaurus is out
- November 18, 2016: I choose Haplocanthosaurus
- May 13, 2018: Back in business
- May 17, 2018: In quest of monsters – last week’s Utah adventure
- July 4, 2018: Haplocanthosaurus goes digital
- July 18, 2018: Proximal caudals of Haplocanthosaurus, from Hatcher (1903)
- August 3, 2018: First caudal vertebrae of the various Haplocanthosaurus specimens
- August 7, 2018: The Haplo project enjoys a brief interlude in realspace
- August 12, 2018: Caudal vertebrae of Haplocanthosaurus delfsi
- October 16, 2018: Sacral pneumatization in sauropods was complex
- December 17, 2018: The Haplocanthosaurus presentation from the 1st Palaeo Virtual Congress is now a PeerJ Preprint
- November 16, 2019: The Snowmass Haplocanthosaurus project is now a museum exhibit
- January 29, 2020: A Haplocanthosaurus in the Salt Wash
- January 23: 2021: Haplocanthosaurus MWC 8028, with Bernie for scale
Post-publications posts
- May 15, 2021: Haplocanthosaurus neural canals are weird, part 1: in which we tell the world
- May 16, 2021: Haplocanthosaurus neural canals are weird, part 2: getting comparative specimens from the grocery store
- February 28, 2022: What’s up with your insanely thick intervertebral discs, Snowmass Haplocanthosaurus?
- September 28, 2022: 3D printing is especially useful for sauropod workers
High-resolution figures

A. Recovered skeletal elements of Haplocanthosaurus specimen MWC 8028. B. Caudal vertebra 3 in right lateral view. C. The same vertebra in posterior view. Lines show the location of sections for D and E. D. Midsagittal CT slice. The arrow indicates the ventral expansion of the neural canal into the centrum. E. Horizontal CT slice at the level of the neural arch pedicles, with anterior toward the top. Arrows indicate the lateral expansions of the neural canal into the pedicles. B-E are shown at the same scale. Wedel et al. (2021: fig. 1).

A. Photograph of a 3D-printed model of the first three caudal vertebrae of Haplocanthosaurus specimen MWC 8028, including endocasts of the neural canal (yellow) and intervertebral joints (blue), in right lateral view, and with the neural canal horizontal. B. Diagram of the same vertebrae in midsagittal section, emphasizing the volumes of the neural canal (yellow) and intervertebral joint spaces (blue). Anterior is to the right. Wedel et al. (2021: fig. 2).

Caudal vertebra 3 of Haplocanthosaurus specimen MWC 8028 in left posterolateral (A), posterior (B), and right posterolateral (C) views, with close-ups (D and E). In A and B, a paintbrush is inserted into one of the lateral recesses, showing that the neural canal is wider internally than at either end. Wedel et al. (2021: fig. 3).

Anatomical features of the neural canal in birds and other dinosaurs. A. MWC 9698, a mid caudal vertebra of Apatosaurus in posterodorsal view. Arrows highlight probable vascular foramina in the ventral floor of the neural canal. B. LACM 97479, a dorsal vertebra of Rhea americana in left anterolateral view. Arrows highlight pneumatic foramina inside the neural canal. C. A hemisected partial synsacrum of a chicken, Gallus domesticus, obtained from a grocery store. Anterior is to the right. The bracket shows the extent of the dorsal recess for the glycogen body, which only spans four vertebrae. Arrows highlight the transverse grooves in the roof of the neural canal for the lumbosacral organ. D. Sagittal (left) and transverse (right) CT slices through the sacrum of a juvenile ostrich, Struthio camelus. The bracket shows the extent of the lumbosacral expansion of the spinal cord. Indentations in the roof of the neural canal house the lumbosacral organ. In contrast to the chicken, the ostrich has a small glycogen body that does not leave a distinct osteological trace. Yellow arrows show the longitudinal troughs in the ventral floor of the neural canal that house the ventral eminences of the spinal cord. Wedel et al. (2021: fig. 4).