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The Hedrick Lab seeks to better understand the interconnected relationship between morphology, phylogeny, and ecology in order to answer the question:

How do morphological innovations lead to the radiation of taxa?

By studying a wide variety of taxa ranging from sharks, to bats, to rodents, to dinosaurs, we assess the impact of morphological evolution on the great diversity of life, past, present, and future.

News

April 8, 2021: Cover of Journal of Morphology!

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Our new paper in collaboration with the Schachner Lab on quantifying variation in lung morphology of African grey parrots using microCT was just published in Journal of Morphology and received the cover! 

Congratulations to all coauthors, but especially to the lead author, Adam Lawson. Adam will be defending his PhD next month. This is certainly a great way to go into a defense!

Lawson, Hedrick, Echols, and Schachner, 2021. Anatomy, variation, and asymmetry of the bronchial tree in the African grey parrot (Psittacus erithacus)

April 1, 2021: Article in Top 100 Downloads of 2020 for Scientific Reports!

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Some very cool work the Hedrick lab did last year with lead authors Dara Orbach (Texas A&M) and Patty Brennan (Mount Holyoke College) on harbor porpoise genitalia was one of the top downloaded papers for 2020 in Scientific Reports (out of more than 21000 papers published in Sci Reports in 2020). It was downloaded more than 14,000 times! Awesome!!

March 12, 2021: Cover of Journal of Anatomy and New Coverboard Paper Out in Herpetological Review

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Our Journal of Anatomy paper on lung morphology of American alligators and ostriches received the cover. Very exciting! Congratulations to my colleagues Emma Schachner, Heather Richbourg, John Hutchinson, and Colleen Farmer!

Also, my recent paper on the effects of coverboard ex situ age and in situ weathering on salamander coverboard usage just came out in Herpetological Review. My colleague Chris Sutherland (Univ. of St. Andrews) and two undergraduates (Fanny Riand and George Bancroft) and I found that red-backed salamanders utilize older coverboards at higher rates than younger ones, but that the weathering process does not appear to impact preference. This suggests non-linear coverboard integration times.

Hedrick et al., 2021: Effects of Coverboard Age and Aging on Salamander Usage. Herp Review.

December 20, 2020: New Paper Out on Archosaur Lung Evolution

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Lungs are the organ of respiration, allowing the majority of tetrapods to live their lives out of the water. In spite of their crucial role in breathing, and their near ubiquitous presence in tetrapods (except for things like lungless salamanders! weird!), they are poorly understood from a morphological standpoint in the vast majority of taxa. This is because they are represented by negative space and require high-powered imaging to visualize in small animals.

My colleague, Emma Schachner, and I have published a paper assessing the morphological structure of ostrich and alligator lungs for the first time using micro-computed tomography in the Journal of Anatomy. In this work, we visualize and quantify interspecific lung differences in these two representatives of the Archosauria, and also assess intraspecific variation and ontogenetic changes. 

https://onlinelibrary.wiley.com/doi/10.1111/joa.13358

August 10, 2020: Salamander Field Work

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We got started setting up some coverboard sites in Hammond, LA and in Tickfaw State Park. Oliver Ljustina (at Southeastern Louisiana University), my wife Sam Cordero, and I braved the summer Louisiana heat to get 200 coverboards set up to monitor Plethodon mississippi (Mississippi Slimy Salamander). 

In October once the boards are integrated, we'll start a spatial capture recapture study. The goal will be to understand differences in population density, land use, and demographics in urban and rural populations. More to come!

April 15, 2020: Special Anatomical Record Volume Out!

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Peter Dodson and I have been working on a special issue for the Anatomical Record on dinosaurs since early 2018 and it just came out! We really appreciate the hard work and patience of all of our contributing authors. 

The volume has 25 original research articles on a wide variety of topics ranging from a description of the largest specimen of T. rex to convergence in tail weaponry in glyptodonts and ankylosaurs to the reconstruction of blood vessels in dinosaur heads. My contribution to the issue concerned paleohistology of horned dinosaurs.

Thanks so much to Jeff Laitman and Kurt Albertine for inviting us to edit the volume. It was a lot of fun!

https://anatomypubs.onlinelibrary.wiley.com/toc/19328494/2020/303/4

Feb 15, 2020: The Future of Museum Collections

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We recently published a manuscript concerning the global effort to digitize specimens in museum collections. We outline two processes that are currently being undertaken in natural history museums, Digitization 1.0 (the conversion of collections into digitized forms within museums) and Digitization 2.0 (the recent push to accelerate the digitization process using the products digitized during Digitization 1.0). Check it out!

 

https://academic.oup.com/bioscience/article-abstract/70/3/243/5729294

Jan 20, 2020: The Evolution of Rodent Limbs

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Our paper on the evolution of proximal rodent limb bones was just published in Scientific Reports. This study aimed to examine internal and external limb geometry of 76 rodent species (including terrestrial, arboreal, semi-aquatic, semi-fossorial, fossorial, and jumping rodents) using microCT. We found that only digging rodents have statistically different limb shapes from other ecological modes. We propose that rodents have been so successful at spreading into new niches and colonizing new areas due to high locomotor plasticity, allowing them to modify their locomotor mode without requiring major body plan modifications. 

Now we're working on expanding our dataset to incorporate other groups including moles, shrews, and of course, bats. 

https://www.nature.com/articles/s41598-019-57144-w