Diminutive fleet-footed tyrannosauroid narrows the 70-million-year gap in the North American fossil record.
Commun Biol
; 2: 64, 2019.
Article
in En
| MEDLINE
| ID: mdl-30820466
ABSTRACT
To date, eco-evolutionary dynamics in the ascent of tyrannosauroids to top predator roles have been obscured by a 70-million-year gap in the North American (NA) record. Here we report discovery of the oldest Cretaceous NA tyrannosauroid, extending the lineage by ~15 million years. The new taxon-Moros intrepidus gen. et sp. nov.-is represented by a hind limb from an individual nearing skeletal maturity at 6-7 years. With a ~1.2-m limb length and 78-kg mass, M. intrepidus ranks among the smallest Cretaceous tyrannosauroids, restricting the window for rapid mass increases preceding the appearance of colossal eutyrannosaurs. Phylogenetic affinity with Asian taxa supports transcontinental interchange as the means by which iconic biotas of the terminal Cretaceous were established in NA. The unexpectedly diminutive and highly cursorial bauplan of NA's earliest Cretaceous tyrannosauroids reveals an evolutionary strategy reliant on speed and small size during their prolonged stint as marginal predators.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Records
/
Dinosaurs
/
Biological Evolution
/
Fossils
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Country/Region as subject:
America do norte
Language:
En
Journal:
Commun Biol
Year:
2019
Document type:
Article
Affiliation country: