Utaurora shares characters and morphology with both radiodonts and Opabinia. Our phylogenetic dataset and analyses supported Utaurora as an opabiniid in 68% of the trees retrieved by analyzing the data, but just in 0.04% for a radiodont.”.
Utaurora comosa from the Wheeler Formation, Utah, USA (Cambrian: Drumian). Utaurora comosa, found in the 500 million-year-old middle Cambrian Wheeler Formation of Utah, was very first explained in 2008 as a radiodont. Upon joining senior author Professor Javier Ortega-Hernándezs lab in OEB, Pates worked with co-lead author Jo Wolfe, postdoctoral fellow in OEB who studies the relationships of fossil and living arthropods, to determine where Utaurora finest fit in the tree of life.
Opabiniids are the first group to have a posterior-facing mouth. Their dorsal intersegmental furrows are precursors to complete body segmentation and their lateral swimming flaps precursors to appendages. Utaurora shares characters and morphology with both radiodonts and Opabinia. While Utauroras anterior structure and eyes were inadequately protected– Opabinia is most identifiable from its frontal proboscis and 5 eyes, the intersegmental furrows along the back and the paired serrated spinal columns on the tail were fully observed..
Minimal morphological observations led Pates and Wolfe to utilize phylogenetic analysis comparing Utaurora with 43 fossils and 11 living taxa of arthropods, radiodonts, and other panarthropods.
” The initial phylogenetic analysis showed it was most closely related to Opabinia,” Wolfe said. “We followed up with more tests to question that outcome utilizing various models of development and data sets to imagine the different type of relationships this fossil might have had.”.
Unlike Opabinia, which was found in the Cambrian Burgess Shale of British Columbia in Canada, Utaurora was found in Utah and, though still Cambrian, is a couple of million years younger than Opabinia. “This means Opabinia was not the only opabiniid, Opabinia was not as distinct a types as we thought,” Pates stated.
When Utaurora was first described as a radiodont in 2008 scientists thought opabiniids and radiodonts formed a monophyletic group called dinocarids. However over the previous 10 to 15 years researchers have discovered over 10 brand-new types of radiodonts, making it possible to see that opabiniids and radiodonts are somewhat different.
” We likewise have more phylogenetic tools to interrogate our results,” Pates stated. “Based on the morphology alone you might make a case for Utaurora being an odd radiodont and also for bringing back the dinocarid idea. However our phylogenetic dataset and analyses supported Utaurora as an opabiniid in 68% of the trees retrieved by examining the data, however only in 0.04% for a radiodont.”.
” Wonderful Life and the description of these fossils occurred before existing evolutionary paradigms. The similarities in between Opabinia and Anomalocaris werent really comprehended yet,” Wolfe stated. “Now we know that these animals represent extinct phases of advancement that relate to modern-day arthropods. And we have tools beyond qualitatively comparing morphological features for a more conclusive positioning within the animal tree of life.”.
Referral: “New opabiniid diversifies the weirdest marvels of the euarthropod stem group” by Stephen Pates, Joanna M. Wolfe, Rudy Lerosey-Aubril, Allison C. Daley and Javier Ortega-Hernández, 9 February 2022, Proceedings of the Royal Society B Biological Sciences.DOI: 10.1098/ rspb.2021.2093.
Funding was offered by the Alexander Agassiz Postdoctoral Fellowship (Museum of Comparative Zoology at Harvard) and a Herchel Smith Postdoctoral Fellowship (University of Cambridge). Extra support was offered by the National Science Foundation (DEB-1856679).
Co-lead authors Pates and Wolfe would like to thank the Division of Invertebrate Paleontology in the Biodiversity Institute at the University of Kansas. These specimens are an invaluable resource for paleontologists to study and can lead to interesting outcomes and discoveries of the type provided here in this important brand-new paper by Pates, Wolfe et al.” Said Professor Bruce Lieberman, Senior Curator.
Creative reconstruction of Utaurora comosa from the Wheeler Formation, Utah, USA (Cambrian: Drumian). Credit: Artwork by F. Anthony
In his book Wonderful Life, the late Stephen Jay Gould, former teacher in the Department of Organismic and Evolutionary Biology at Harvard, promoted the “unusual marvel” stem-group arthropods Opabinia and Anomalocaris, found in the Cambrian Burgess Shale, turning them into icons in pop culture. While the “terror of the Cambrian Anomalocaris– with its radial mouth and spiny understanding appendages– is a radiodont with numerous family members, the five-eyed Opabinia– with its unique frontal proboscis– stays the only opabiniid ever discovered. That is, till now.
An international team of scientists led by Harvard University validate that a specimen formerly thought about a radiodont is in reality an opabiniid. The brand-new study in Proceedings of the Royal Society B used unique and robust phylogenetic techniques to verify Utaurora comosa as just the second opabiniid ever found and the very first in over a century.
Utaurora comosa from the Wheeler Formation, Utah, USA (Cambrian: Drumian). Holotype and just known specimen, accessioned at the Division of Invertebrate Paleontology in the Biodiversity Institute at the University of Kansas. Credit: Photograph by S. Pates
Utaurora comosa, discovered in the 500 million-year-old middle Cambrian Wheeler Formation of Utah, was first explained in 2008 as a radiodont. Co-lead author Stephen Pates, former postdoctoral fellow in the Department of Organismic and Evolutionary Biology (OEB) at Harvard, very first came across the specimen at the University of Kansas Biodiversity Institute & & Natural History Museum while a graduate student. Pates was studying the diversity of radiodonts and felt this specimen did not exactly fit with a real radiodont. Upon joining senior author Professor Javier Ortega-Hernándezs lab in OEB, Pates worked with co-lead author Jo Wolfe, postdoctoral fellow in OEB who studies the relationships of fossil and living arthropods, to figure out where Utaurora finest fit in the tree of life.
