Feredocodon chowi was a mouse-sized shuotheriid mammaliaform from what is now Inner Mongolia, China, about 168–164 million years ago. Its unusual teeth once helped place its relatives near the lineage that includes platypuses; a 2024 study instead argues that their distinctive molars fit better with docodontans. The “chimera” comparison describes this surprising mix of evolutionary clues—not a fossil made from different animals.
What was the “platypus-like” animal?
Feredocodon chowi was a shuotheriid: an extinct mammaliaform known from Middle Jurassic fossils associated with the Daohugou locality in Inner Mongolia. The American Museum of Natural History describes shuotheriids as mouse-sized and dates them to about 168–164 million years ago. They lived during the age of dinosaurs, but the available reports do not identify a particular dinosaur species from the same locality passage.
As an Amazon Associate I earn from qualifying purchases.
Calling it “platypus-like” refers to an older idea about evolutionary relationships, not a claim that Feredocodon looked or lived like a modern platypus. It was not a platypus, and the findings described here do not establish it as a direct platypus ancestor. The evidence also does not establish that it laid eggs.
Why did its teeth look like a chimera?
The puzzle lies in the layout of the lower molars. Shuotheriid molars have a basin-like feature called a pseudotalonid positioned in front of the trigonid. In the tribosphenic molars typical of living therians—the broad group that includes marsupials and placental mammals—the talonid sits behind the trigonid instead.
#1 Best Overall
- The allosaurus was a large, theropod predator that lived roughly 156 to 130 million years ago and may have grown up to 39 feet (12 m) long
- Cast of the large toe ungual from the towering bipedal carnivorous dinosaur of the Jurassic
- The original claw was unearthed in the Morrison formation at the Cleveland-Lloyd Quarry in central Utah
- Detailed cast replica. 7 inches. Museum quality resin cast made in the USA
That unusual arrangement made the teeth hard to fit into a straightforward evolutionary story. As Jin Meng, a curator at the American Museum of Natural History and a corresponding author on the studies, put it: “Since the 1980s, the perplexing tooth shape seen in shuotheriids has been a barrier to our efforts to understand early mammal evolution.”
The 2024 study proposes that the shuotheriid pattern is homologous to the pattern in docodontans: in other words, the similarities reflect a shared evolutionary feature rather than merely a superficial resemblance. On that interpretation, the teeth point away from the traditional placement near monotremes, the group that includes the platypus.
Rank #2
- Complete Prehistoric Experience: Seamlessly combine VEOJEIN's 3D Mosquito in Amber Resin with the uniquely detailed resin base to capture the essence and fascination of the dinosaur era.
- Important Note: The mosquito in amber product has a seam due to the manufacturing process. This seam may be visible from certain angles. While we strive to minimize its appearance, it is not entirely avoidable. We want to be transparent about this aspect of the product.
- Perfect Gift for Dino Enthusiasts: Enclosed in themed packaging, this bundle becomes an unforgettable present for enthusiasts and collectors alike, merging artistry, history, and vintage charm. Versatile Decor & Collectible: Elevate your space with this bundle that serves both as an exquisite decor element and a must-have for collectors passionate about dinosaurs, amber, and the prehistoric world.
- High-Quality Craftsmanship: Meticulously designed and crafted from durable resin, both pieces in the bundle exhibit unmatched attention to detail, ensuring you have not just collectibles but pieces of art.
- Engage & Educate: Beyond aesthetics, the bundle inspires curiosity and a deeper understanding of the prehistoric world, making it an engaging conversation starter and a tool to ignite passion for history and learning.
What does the revised evolutionary tree propose?
The researchers’ revised analysis proposes that docodontiforms, allotherians and holotherians split from a Morganucodon-like ancestor along separate evolutionary paths. This is a proposed interpretation of the evidence, not an uncontested final map of early mammal relationships. Its importance is that the position of the pseudotalonid changes how scientists interpret the resemblance between shuotheriid teeth and those of other mammaliaforms.
That is the useful sense of “chimera” here: a fossil whose features complicate familiar categories and reveal a mosaic of evolutionary history. It does not mean Feredocodon was a literal blend of two animals, nor does it make “part platypus, part docodontan” a scientifically accurate description.
Rank #3
- Includes a 5-inch Megalodon shark tooth replica and a 7-inch Allosaurus claw replica, cast from real fossil specimens
- Megalodon Tooth Replica – A lifelike reproduction of the giant Miocene-era shark’s massive tooth, showcasing the size and power of one of history’s largest ocean predators
- Allosaurus Claw Replica – A museum-quality cast of the large toe claw from this towering Jurassic predator, reflecting its sharp hunting adaptations
- Highly Detailed Fossil Casts – Crafted from durable resin with intricate texture, offering an authentic look and feel
- Great for Collectors & Educators – Appropriate for fossil enthusiasts, paleontology displays, classroom learning, or unique decor inspired by prehistoric giants
What can the fossils tell us about the mammalian middle ear?
The studies also examine structures in the lower jaws of Feredocodon and Dianoconodon youngi, a Morganucodon-like mammaliaform from the Early Jurassic Lufeng Biota. These fossils provide evidence about the transition of bones associated with the jaw joint toward structures used in hearing.
The American Museum of Natural History’s account says Feredocodon already had a mammalian middle ear adapted exclusively for hearing. The Chinese Academy of Sciences describes the specimens as illuminating changes in the role of the articular-quadrate jaw joint and the mandibular middle ear. Together, these findings show why the fossils matter beyond their teeth: they preserve evidence of change in both feeding anatomy and hearing-related structures.
Quick Recap
Best Value
- Replica Chirostenotes dinosaur claw – approx. 4.5 inches (11.43cm)
- Species: Chirostenotes pergracilis, Late Cretaceous (~76.5 million years ago), Alberta, Canada
- Realistic texture and anatomical accuracy – great for collectors, educators, and fossil enthusiasts
- Useful in paleontology education, museum displays, or as a unique prehistoric gift
- Display-ready fossil replica (stand not included)
Rank #4
- Genuine Jurassic Gallery Fossil: Contains an authentic Triceratops bone fragment from the late Cretaceous period (approx. 67 million years old), ethically sourced from the Hell Creek Formation, Montana, USA.
- Elegant Lucite Display Case: Housed in a 4 x 3.25 x 1 inch (10.5 x 8.5 x 2.5 cm) transparent Lucite case with a magnetic lid for secure and stylish presentation.
- Unique Natural Specimen: Each bone fragment varies in shape, size, and color, reflecting the natural diversity of Triceratops fossils from the Cretaceous era.
- Distinctive Triceratops Features: Represents the Triceratops, known for its three horns, large frill, and up to 800 teeth, used for defense, foraging, and display.
- Historical Significance: From a herbivore that roamed alongside Tyrannosaurus rex, feeding on prehistoric plants like palms and cycads.
Sources and further reading
- American Museum of Natural History: 2024 report on the Jurassic mammaliaforms, their teeth, age and middle-ear evidence.
- Chinese Academy of Sciences: summary of the tooth interpretation, proposed evolutionary relationships and jaw structures.
- Nature: primary study on shuotheriid molars.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitches
