Aletopelta: The Wanderer Shield of the Late Cretaceous

Aletopelta: The Wanderer Shield of the Late Cretaceous

Welcome to a journey back in time, to an era when dinosaurs roamed the Earth. Today, we’re going to delve into the world of a particular dinosaur, the Aletopelta. This herbivorous wanderer from the Late Cretaceous period has a fascinating story to tell, and we’re here to uncover it.

Aletopelta Key Facts

Aletopelta pronunciationa-LEE-to-PEL-tuh
Meaning of nameWanderer shield
Type SpeciesAletopelta coombsi
When it Lived83.5 to 70.6 MYA
PeriodLate Cretaceous
EpochLate/Upper Campanian
Length16.0 ft
Height4.9 ft
Weight2.2 tons
MobilityMoved on all four
First Discovery1987 by Bradford Riney
Location of first findCalifornia, USA
First Described by1996 by Thomas Deméré and Walter Preston Coombs
HolotypeSDNHM 33909

Aletopelta Origins, Taxonomy and Timeline

Discover the Aletopelta - A four legged herbivore dinosaur from the Tetrapod group, living where modern day California lies around 83.5 to 70.6 MYA.

The name Aletopelta is derived from the Greek words “aletes” meaning wanderer and “pelte” meaning small shield. It’s a name that conjures images of a roaming herbivore protected by its shield-like armor as it traverses the prehistoric landscapes.

It belongs to the Ankylosauria suborder, known for its quadrupedal armored dinosaurs. Within this group, Aletopelta is the sole member of its own family and genus, making it a unique specimen in the world of paleontology. The type species, Aletopelta coombsi, is named in honor of Walter Preston Coombs, a renowned paleontologist. This dinosaur’s lived in the Late Cretaceous period, specifically the upper Campanian stage.

Discovery & Fossil Evidence

''Aletopelta coombsi'' fossil in San Diego.
ケラトプスユウタ, CC BY-SA 4.0, via Wikimedia Commons

This story of discovery begins in 1987 in California, USA. Bradford Riney, an amateur fossil hunter, stumbled upon the first evidence of this dinosaur’s existence. The find was significant, marking the discovery of a new dinosaur species. The fossil consisted of a partial skeleton that, at the time of deposition, had washed out to sea and was scavenged upon by sharks and other invertebrates before forming a miniature reef.

Thomas Deméré and Walter Preston Coombs later described the fossil and the genus in detail in 1996. The holotype, SDNHM 33909, provided valuable insights into the dinosaur’s physical characteristics and lifestyle. The preservation of the fossils allowed for a detailed study of Aletopelta’s unique features, contributing significantly to our understanding of this dinosaur.

Aletopelta Size and Description

Aletopelta was a four-legged herbivore, a characteristic shared with many other dinosaurs of its group. Its body was likely covered in protective armor–a feature implied by its name, “wanderer shield”. This armor would have served as a defense mechanism against predators. The specific details of its physical characteristics, such as its head, neck, vertebrae, limbs, tail, and skin, remain a subject of ongoing research.

Size and Weight of Type Species

Slate Weasel, CC0, via Wikimedia Commons

The size and weight are topics of much speculation and debate among paleontologists. As of now, there are no definitive measurements available. Originally its length was estimated to be 19.7 feet. Years later, a different study conducted by Gregory S. Paul suggested a length and weight of 16 feet and 2 tons.

The Dinosaur in Detail

Aletopelta, despite being a relatively lesser-known dinosaur, has some unique features that set it apart. Its protective armor, implied by its name, suggests that it was well-adapted for survival in a world filled with predators. This armor, combined with its herbivorous diet, paints a picture of a dinosaur that was more of a peaceful wanderer than a fierce predator.

The holotype is, as of yet, the only specimen. It is possible that it was a juvenile, given the fact that not all of its growth plates were fused. Through the study of this fossil we have been able to piece together a more complete picture of this fascinating dinosaur.

The Aletopelta in its Natural Habitat and Environment

The Late Cretaceous period, when this dinosaur roamed the Earth, was a time of significant geological and climatic changes. At the time, North America was not one continent but two–split into west and east by an interior seaway. Aletopelta would have been found on the western half known as Laramidia. The environment was diverse with a mix of lush forests, open plains, and vast oceans. A habitat perfect for an herbivore.

Aletopelta’s diet likely consisted of a variety of plants, including ferns, cycads, and conifers. Its four-legged locomotion suggests that it was a slow-moving dinosaur that spent much of its time grazing. The dinosaur’s social behavior remains a mystery, but it’s possible that it lived in herds for protection against predators.

Its presence would have had a significant impact on its environment. Moreover, as a large herbivore, it would have played a crucial role in shaping the landscape and maintaining the balance of the ecosystem.

Interesting Points about Aletopelta

  1. It is the only known dinosaur from the Late Cretaceous period that was discovered in California.
  2. The dinosaur’s name translates to “wanderer shield”, hinting at its likely nomadic lifestyle and protective armor.
  3. It is unique in being the sole member of its own family and genus.
  4. The type species, Aletopelta coombsi, is named after Walter Preston Coombs, a renowned paleontologist.

Contemporary Dinosaurs

In the Late Cretaceous period, a fascinating dance of survival played out among the prehistoric giants. At the heart of this dance was the Aletopelta, a dinosaur that was as intriguing as it was formidable. It shared this dance with other North American dinosaurs, such as the Ankylosaurus, Edmontia, and Tyrannosaurus. 

The herbivorous Aletopelta was roughly the same size as its contemporary and relative, the Ankylosaurus. Alongside these ankylosaurs was the smaller Edmontia. They all would have vied for the same food resources, their paths crossing in a silent contest of wills at the feeding grounds. These three herbivores were armored dinosaurs, their bodies covered in a protective shell of bony plates. This feature is a testament to the harsh realities of their shared environment.

These herbivores had to contend with the towering menace of the Tyrannosaurus. This colossal predator, significantly larger than all of them, was a constant threat. The Aletopelta, despite being a peaceful herbivore, was not defenseless. Its body was a fortress and its tail was a weapon capable of delivering powerful blows. The Tyrannosaurus in its pursuit of prey would have had to weigh the risks of attacking such a well-protected quarry.

In this prehistoric world, the Aletopelta was a symbol of resilience and adaptation. It coexisted with dinosaurs both larger and smaller, each interaction showcasing its ability to survive. The Aletopelta, Ankylosaurus, Edmontia, and Tyrannosaurus each played their part in the grand drama of life, still fascinating to us today. 

List of All Dinosaurs

We have created a list of all dinosaurs we have covered here, sorted across the seven main groups of dinosaurs. We also include information about their type of diet, (omnivore, herbivore or carnivore) and the time they lived.

Frequently Asked Questions

What does the name mean?

The name translates to “wanderer shield”, derived from the Greek words “aletes” (wanderer) and “pelte” (small shield).

When did this dinosaur live?

It lived during the Late Cretaceous period, around 83.5 to 70.6 million years ago.

What did it eat?

As an herbivore, it likely fed on a variety of plants including ferns, cycads, and conifers.

Where was it discovered?

The first fossils were discovered in California, USA.

Who discovered this dinosaur?

Aletopelta was first discovered by Bradford Riney in 1987.


The information in this article is based on various sources, drawing on scientific research, fossil evidence, and expert analysis. The aim is to provide a comprehensive and accurate overview of the Aletopelta. However, please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

Article last fact-checked: Joey Arboleda, 07-26-2023

Featured Image Credit: Nobu Tamura, CC BY-SA 4.0, via Wikimedia Commons