Category: New Research

Three Ichnoplanet students at the University of Saskatchewan receive awards from the International Association of Sedimentologists!

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Dr. Maximiliano Paz has received the International Association of Sedimentologists (IAS) Postdoctoral Research Grant. He is currently studying the sedimentology and ichnology of the Cambrian-Ordovician Los Cabos Series. These funds will be used to cover one month of fieldwork expenses to log 4000 m of the succession in the rocky cliffs of western Asturias, Spain.

Jack Milligan has received the IAS Judith McKenzie Fieldwork Award. He is studying the sequence stratigraphy and taphonomy of dinosaur bones including describing osteic bioerosion trace fossils from the latest Cretaceous Frenchman Formation. This funding will cover fieldwork expenses to measure coastal floodplain and fluvial outcrops along the Frenchman River Valley of southwestern Saskatchewan.

Federico Wenger also received the IAS Judith McKenzie Fieldwork Award. He will be studying the sequence stratigraphy and ichnology including the degree of bioturbation, ichnodisparity, and ichnodiversity to understand the different environmental zones of the Devonian Talacasto Formation, in the geological province of Precordillera, western Argentina. This funding will help finance the trip to the study area.

Congratulations to Maximiliano, Jack, and Federico, and best of luck with your fieldwork, and thank you to the International Association of Sedimentologists for helping fund Ichnoplanet research at USask!

Written by Jack Milligan

Dr. Anthony Shillito receives Banting Postdoctoral Fellowship to conduct research at USask on animal aquatic-terrestrial transition

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Dr. Anthony Shillito from the University of Oxford, England, is one of the recent recipients of the Banting Postdoctoral Fellowship, which allows exceptional scholars to continue their research with the help of federal funding.

Dr. Shillito’s project at the University of Saskatchewan will be focused on understanding why animals began the transition from marine to terrestrial, and the factors that may have played a part in establishing terrestrial faunal communities. He has previously conducted fieldwork looking into this research question in places such as the United Kingdom, Australia, and the Canadian Arctic. His work will look at this transition through the perspective of the trace fossil record including burrows and trackways, including analysis of the sedimentology associated with these important fossils. Congratulations on receiving this prestigious award Anthony, we are excited to have you join our research group!

You can read more of Dr. Shillito’s research on his ResearchGate page!

Written by Jack Milligan

Modern animal life could have arisen in a storm-dominated deltaic environment

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Our understanding of how and where the ancestors of modern life evolved has been the question of many paleontologists for a long time. Recently, an international team of sedimentologists and paleontologists, including Dr. Luis Buatois, Dr. Gabriela Mángano, and Dr. Maximiliano Paz, demonstrated that a world-famous Cambrian soft-bodied fossil assemblage in Yunnan province, China, lived and died in a delta front environment affected by storms. The Chengjiang Biota records the exquisite preservation of soft-bodied marine invertebrates, including worms, early arthropods, and early vertebrates. This assemblage is around 518 million years old, around the time of the famous Cambrian explosion, where modern communities of animals first started to truly diversify. The Chenjiang biota has a similar faunal makeup to the Burgess Shale biota from British Columbia, Canada. The team analyzed a core taken from Cambrian outcrops in Yunnan, China, and discovered that the sequence of strata was formed in a shallow marine, deltaic environment. High rates of sedimentation and indications of high salinity point to this deltaic environment being dominated by storms and river floods. These kinds of sediments help us to understand the exceptional taphonomy of fossils from these Cambrian assemblages.

Figure. Block diagram showing the storm-flood-dominated delta and associated cores showing depositional sequences. (From F. Saleh et al., 2022)

The full article can be accessed in Nature Communications.

Written by Jack Milligan

Associated Champsosaur skeleton in Southwest Saskatchewan discovered by Jack Milligan

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Following the K-Pg mass extinction event which wiped out the non-avian dinosaurs, the swamps and floodplains of southwest Saskatchewan were populated by an assortment of small to medium-sized vertebrates including turtles, crocodiles, early mammals, and a now-extinct group of semi-aquatic reptiles known as champsosaurs. During a joint research expedition near the town of Climax, Saskatchewan by the Royal Saskatchewan Museum and Carleton University in Ottawa in August 2020, an associated skeleton of a champsosaur was recovered by Jack Milligan. The champsosaur was collected in a terrestrial shale horizon around 3 m above the K-Pg boundary, from the Paleocene-aged Grey facies of the Ravenscrag Formation. The Grey facies records a low-energy, vegetated swamp environment. 

Champsosaur hind foot (middle right in image). Photo by Jack Milligan.

This skeleton is between 35-40% complete and is comprised of several dorsal and caudal vertebrae with intact neural arches and transverse processes, incomplete bones from all four limbs including a humerus and femurs, dozens of ribs, and several elements making up the pectoral and pelvic girdles. Numerous gastralia as well as a near complete hind foot were found in situ upon examination of the shale horizon from which the bones had eroded out. More fieldwork is needed to try and recover cranial material to affirm an accurate taxonomic identification of this specimen.

You can read more about the discovery in this Usask news article.

Written by Jack Milligan

Note: Jack recently joined the ichnofamily at Usask as an M.Sc. student! You can read more about him on his ichnoplanet profile, or follow him on ResearchGate or Twitter. –Brittany

Were all trilobites fully marine?

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Trilobites, the poster-fossil of the Paleozoic, have long been considered to be invariably fully marine. Collaborative work between Dr. Mángano, Dr. Buatois, and Argentinian colleagues questions this assumption. Through the integration of multiple datasets they report uncontroversial evidence of the exploration of tide-dominated estuaries by some trilobite groups (olenids & asaphids) throughout the Furongian to Middle Ordovician. Thick siliciclastic successions in northwest Argentina expose vertically-repeating nearly-identical environments and allowed for the comparison of body-fossil and trace-fossil data in tide-dominated estuaries through time. Their research indicates two forays into brackish water, first the colonization of the outer portion of estuaries by olenids, followed by the colonization of inner to middle estuarine zones by asaphids.

The full article is available in the Proceedings of the Royal Society B (including some fantastic photos of trilobite trace fossils in the Supplementary Info!).

Figure. Time-environment matrix showing protracted trilobite expansion into marginal-marine estuarine settings. (From Mángano et al., 2021)

Written by Brittany Laing