Aphaurosuchus | The Feeble Bite Crocodile of the Late Cretaceous

Aphaurosuchus | The Feeble Bite Crocodile of the Late Cretaceous

In the late Cretaceous Period, around 83.5 to 66.0 million years ago, a unique crocodyliform roamed the land that is now Brazil. Named Aphaurosuchus and discovered in the lush terrains of Sao Paulo State, this creature offers a fascinating glimpse into the diverse and complex ecosystems of prehistoric South America.

You got it right, today we are going to talk, not about a dinosaur, but about crocodile evolution! Dinosaurs are cool, but crocs are even cooler in my eyes! Moreover, this specimen was described based on an almost complete skeleton. The skull was CT-scanned and its description is supported by the 3D model produced.

Aphaurosuchus Key Facts

KeywordFact
Pronunciationaf-aw-roh-SOO-kus
Meaning of nameFeeble Bite Crocodile
GroupCrocodyliformes
Type SpeciesAphaurosuchus escharafacies
Other speciesAphaurosuchus kaiju
DietCarnivore
When it Lived89.8 and 72.1 MYA
PeriodLate Cretaceous
EpochConiacian to the Campanian
LengthNot available
HeightNot available
WeightNot available
MobilityMoved on four legs
First Discovery2012 by Laboratório de Paleontologia led expedition
Described by2021 by Gustavo Darlim, Felipe Montefeltro, and Max Langer
HolotypeLPRP 0697
Location of first findFurnas Farm, Sao Paulo State, Brazil

Aphaurosuchus Origins, Taxonomy and Timeline

The name Aphaurosuchus derived from Greek “aphauros” meaning “feeble” or powerless and the “souchos” the egyptian name for crocodile. The name then refers to the weak bite this crocodile had. The type species name (A. escharafacies) is derived from both Latin a Greek and means “scar face” and refers to the cut present on the left jugal (cheek) of the holotype specimen.

Discover Aphaurosuchus, a baurusuchid crocodile from Late Cretaceous Brazil, known for its unique weak bite.

Taxonomically, Aphaurosuchus falls under the group Crocodylomorpha and belongs to the Baurusuchia. This classification places it among the Notosuchia, a group of terrestrial crocodyliforms known for their unique adaptations and diverse morphologies. Baurusuchids, distinct from other crocodylomorphs by their reduced tooth formula and their laterally compressed snout, were notable predators of their time, and are 

Aphaurosuchus lived during the Late Cretaceous Period, specifically from the Coniacian to the Campanian, roughly between 89.8 and 72.1 million years ago. 

Discovery & Fossil Evidence

Aphaurosuchus was first discovered in 2012 during an expedition led by the Laboratório de Paleontologia in Sao Paulo State, Brazil. The site is situated near the town of Jales on the Furnas farm, is located within the Adamantina Formation (Bauru Basin). It yielded an almost complete skeleton of this remarkable creature. This find, catalogued as LPRP 0697, provides a comprehensive view of its anatomy and morphology, offering significant insights into the life and environment of this Baurusuchid. 

Discover Aphaurosuchus, a baurusuchid crocodile from Late Cretaceous Brazil, known for its unique weak bite.
Image Credit: Dinopedia.fandom

The fossil evidence includes a well-preserved skull and articulated postcranial elements, which are crucial for understanding the physical characteristics and functional morphology of Aphaurosuchus. More importantly the skull was CT scanned, and a 3D model produced. This helps paleontologist to understand the inner cranial anatomy of this specimen.

Additionally, another specimen was described in 2024 by Martins and colleagues, and a second species, A. kaiju, was described. This second specimen includes cranial material only. Like the holotype of the type species, it was found near the town of Jales in the Adamantina Formation, but on a roadside outcrop. Both sites are dated to the Coniacian to the Campanian. 

Aphaurosuchus Size and Description

Short Description of Aphaurosuchus

Two species of this croc have been described until now. The type species is the only one to be almost complete, with a skull and postcranial remains. The description I wrote below is then based on this species only. 

Let’s talk about the skull first. It’s a typical crocodylomorph skull, with two temporal fenestrae, a mandibular fenestra, a large and flat posterior table. The snout is elongated and constricted right behind the last postcanine. The anterior section of the skull is heavily ornamented. Notably, the jugal and lacrimal house several ridges and fossae. Dental occlusion occurs and the mandible canine goes through the anterior-most part of the snout, behind the external naris. In ventral view, the palate is largely formed by the pterygoids and the attached ectopterygoids. The occiput is broad with a reduced height.

The neck was strong, supporting the head, and leading to a stout quadrupedal body. The vertebrae of Aphaurosuchus were well-developed, supporting a powerful torso and limbs. It had sturdy legs that suggest it moved primarily on all fours, like several crocodylomorph at the time. The tail was likely muscular and possibly used for balance and swift movements. Its body, like its relative, was covered in osteoderms.

Size and Weight of Type Species

Estimating the size and weight of Aphaurosuchus involves looking at its relatives and the detailed fossil evidence available. Baurusuchids generally ranged from 13.0 to 20.0 feet in length. Aphaurosuchus likely fell within this range, possibly measuring around 16.0 to 19.0 feet long. This length is based on comparisons with similar species and the proportional analysis of its skeletal remains. Weight estimates for Aphaurosuchus vary, but it could have weighed between 440.0 and 1,320.0 pounds. 

The Croc in Detail

Aphaurosuchus stands out among its contemporaries due to several unique features. One of the most intriguing aspects is its weak bite (compared to other crocs), which is unusual for a predator of its size. This characteristic suggests it had adapted to a specific feeding strategy, possibly relying on softer prey or scavenging. The intricate structure of its skull, with pronounced ornamentation, hints at possible social or defensive roles.

The skeletal structure of Aphaurosuchus reveals a creature built for power and stability. Its robust limbs and well-developed vertebrae indicate it was capable of quick bursts of speed and agile movements. Current scientific reconstruction suggest it was standing on its phalanges for both the manus and pes. The tail, muscular and flexible, would have been a crucial tool for balance and swift directional changes. These physical adaptations highlight its role as a terrestrial predator in its ecosystem.

The holotype was CT-scanned, and a qualitative 3D reconstruction enabled specialists to provide a full detailed description of each cranial bone. Particularly, the initial description published in 2021 provided a full reconstruction of braincase bones. Those are known to be fragile and to be rarely found in the fossil record. They are crucial for paleontologists in order to infer the earring system of the animal and its general way of life. Moreover, the CT scan data provided a full picture of the dentition, including the root morphology of each teeth. No replacement teeth were found on the specimen.

Contemporary Taxa

The world of Aphaurosuchus was a vibrant and dynamic ecosystem teeming with a variety of taxa, including dinosaurs, that each played a distinct role. One of the dinosaur that shared the landscape with Aphaurosuchus was Noasaurus. Although Noasaurus is from a later geological stage than Aphaurosuchus, they might have crossed paths during the Campanian. Noasaurus is a small theropod, distinguished by its unique claw, which carved out its own niche within the ecosystem. Unlike the larger Aphaurosuchus, which likely held the position of a top predator, Noasaurus focused on preying on smaller animals and insects. This dietary preference allowed Noasaurus to thrive without competing directly with the more formidable Aphaurosuchus, showcasing a well-balanced ecological community.

During the Campanian, the massive sauropod Saltasaurus roamed the land, its presence significantly influencing the predatory strategies of Aphaurosuchus. Saltasaurus was a large herbivore and the first sauropod genus known to be equipped with heavy armor and considerable size, making it a daunting target for any predator. This formidable defense likely led Aphaurosuchus to target the younger or weaker individuals of the Saltasaurus population, adapting its hunting techniques to the challenges posed by such enormous prey. The interactions between these species underscore the complexity of their shared environment, where survival often hinged on strategy and opportunity.

Adding to this intricate web of life was Bonapartenykus (Campanian-Maastrichtian), a small, bird-like dinosaur from the Alvarezsauridae. Bonapartenykus likely subsisted on insects and small vertebrates, further diversifying the dietary habits within the ecosystem. The presence of such varied diets among these contemporaries highlights the rich and complex food web that sustained life during the Late Cretaceous. Aphaurosuchus, amidst these contemporaries, navigated a world full of diverse and specialized species, each contributing to the balance and dynamism of their prehistoric habitat.

Interesting Points about Aphaurosuchus

Aphaurosuchus in its Natural Habitat

Aphaurosuchus lived in a diverse and lively ecosystem during the Late Cretaceous Period. This environment was a mix of lush vegetation, semi-arid regions, and wide river systems, offering various habitats for different species. The warm climate and changing sea levels of the time shaped the land and types of plants that grew there. The Bauru Basin, where Aphaurosuchus was found, formed due to the break-up of the continent when the Atlantic Ocean opened up. This basin spread across parts of modern-day Brazil and became a hotspot for fossils.

The Bauru Basin was rich in life, with a wide variety of plants and animals. As a carnivore, Aphaurosuchus likely ate smaller animals and possibly scavenged for food. Its weak bite meant it probably avoided large, tough prey and instead hunted softer, easier-to-catch creatures. The diverse food supply in the basin included algae, mollusks, crustaceans, turtles, lizards, snakes, other dinosaurs, mammals, and birds, providing plenty of options for Aphaurosuchus.

Aphaurosuchus was likely a solitary hunter, based on the few fossils found and the territorial nature typical of many crocodyliforms. Its strong tail and limbs suggest it was built for quick, sudden movements, which would have been useful for ambushing prey and escaping larger predators. The area where it lived had fine sandstones and mudstones, indicating a river-based environment with a semi-arid climate. As the climate became drier, the land developed into plains, braided rivers, and ponds, creating a challenging landscape for Aphaurosuchus to navigate and dominate.

Frequently Asked Questions

What does the name Aphaurosuchus mean?

Aphaurosuchus means “Feeble Crocodile,” referring to its notably weak bite.

When did Aphaurosuchus live?

Aphaurosuchus lived during the Late Cretaceous Period, from approximately 89.8 and 72.1 million years ago.

Where was Aphaurosuchus discovered?

Aphaurosuchus was first discovered at Furnas Farm in Sao Paulo State, Brazil.

What did Aphaurosuchus eat?

As a carnivore, Aphaurosuchus likely fed on smaller animals and possibly carrion, relying on softer prey due to its weak bite.

How big was Aphaurosuchus?

Based from the bone fragments and comparison with other member in its group, rough estimate suggests that Aphaurosuchus measured between 16.0 and 19.0 feet in length and weighed between 440.0 and 1,320.0 pounds.

What is unique about Aphaurosuchus’s bite?

Despite its size, Aphaurosuchus had a surprisingly weak bite, which is unusual for a predator.

Sources

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 Aphaurosuchus. However, please be aware that our understanding is constantly evolving as new discoveries are made.

This article was last fact checked: Joey Arboleda, 07-16-2024

Featured Image Credit: SeismicShrimp, CC BY 4.0, via Wikimedia Commons

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