Newly Unearthed Dinosaur Species in Utah Thrived Amidst Monumental Ecological Transitions

Pictured here is the artist’s representation of Iani smithi, a recently unearthed dinosaur species. This discovery provides a profound understanding of the massive ecological transformations that took place in North America about 100 million years ago. The survival of this species during a period of global warming reflects similarities to the ongoing climate crisis. Credit: Jorge Gonzalez

Understanding dinosaurs’ adaptation to mid-Cretaceous ecological changes.

A groundbreaking study uncovers a new dinosaur species, Iani smithi, and its crucial role in providing insights into the considerable ecological changes that occurred in North America approximately 100 million years ago. Iani smithi, originating from the Cedar Mountain Formation in Utah, existed during the early Late Cretaceous and belonged to an early lineage of ornithopod dinosaurs. Coupled with other findings from the same geological layer, the discovery indicates that various significant dinosaur groups persisted amidst the era’s ecological turmoil. Moreover, the authors emphasize the importance of this discovery in linking the extinction of early ornithopods in North America to a noteworthy global warming period, which curiously echoes today’s climate crisis.

A newfound dinosaur species from Utah reveals substantial ecological changes in North America around 100 million years ago, as outlined in a study released on June 7, 2023, in the open-access journal PLOS ONE. The study was conducted by Lindsay Zanno of the North Carolina Museum of Natural Sciences, along with her team.

The transition from the Early to the Late Cretaceous Period witnessed substantial global ecosystem restructuring, coinciding with a spike in global temperatures. The western North American fossil record documents this ecological shift extensively for marine environments, but land ecosystems remain underexplored. In this research, Zanno and her colleagues unveil a new dinosaur from Utah’s early Late Cretaceous Cedar Mountain Formation.

Positioning of the Iani smithi holotype locality. (A) Global map indicating the location of the Mussentuchit Member outcrop in central Utah, western North America, along with a stratigraphic section at the quarry with dated ash layers; and (B) visual depiction of the preserved skeletal elements of the holotype specimen. The preserved elements are color-coded on the left-facing skeletal, regardless of their origin from the body’s right or left side. Exact placements of chevrons and ribs remain unknown due to poor preservation. Credit: Zanno et al., 2023, PLOS ONE, (CC-BY 4.0)

The newly identified dinosaur, Iani smithi, lived around 100 million years ago. Its single fossil specimen consists of a well-preserved skull and sections of the spine and limbs. The name originates from Ianus, a Roman deity overseeing transitions, symbolizing the mid-Cretaceous’s transformative world.

Iani is a member of an early offshoot of the ornithopod dinosaurs, primarily bipedal herbivores including renowned examples like Iguanodon and Tenontosaurus. Iani is the first early-diverging ornithopod known from North America’s Late Cretaceous.

This discovery, combined with other recent findings from the same geological layer, suggests that several main dinosaur groups survived into the early Late Cretaceous despite the era’s ecological transitions. However, the roles and longevity of these survivors remain uncertain. Given that Iani and its nearest relatives are typically found in ancient coastal habitats along the now-disappeared Western Interior Seaway’s shores, the authors propose further investigations into similar aged coastal deposits to find more evidence addressing these unresolved questions.

The authors add: “Early ornithopods were once a prevalent part of North American ecosystems, but their survival into the Late Cretaceous was unknown. The unearthing

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More about Dinosaur Discovery

• Link to PLOS ONE Journal Article
• Research at the North Carolina Museum of Natural Sciences
• Information on the Cedar Mountain Formation
• More on Ornithopod Dinosaurs