Evidence for Mammalian Red Blood Cells in Dinosaur Fossils: A Morphological Reappraisal
All articles by Wretch Fossil are here: http://www.wretch.cc/blog/lin440315&category_id=0
Introduction
The debate surrounding the nature of red blood cell (RBC)-like structures in fossilized dinosaur remains has intensified in recent years. Some researchers have proposed that dinosaurs, traditionally classified as reptiles, may in fact share closer affinities with mammals, as inferred from the morphology of preserved blood elements. Here, we examine a selection of images from the Flickr album (https://www.flickr.com/photos/fossil_lin/albums/72177720307335322 ) which depict cellular morphologies highly consistent with extant mammalian RBCs. These images include concave, anucleate, and highly deformable cells confined within putative blood vessels—characteristics that differ from the elliptical, nucleated RBCs of reptiles and birds.
Figure 1: Fossil fragment with erythrocyte-like impressions measuring ~18–21 µm across, showing characteristic biconcave shape.
Figure 4: Close-up of red, round, and concave cell labeled ‘A’ within a fossilized vessel. Interpreted as a mammalian RBC by original researchers and later publications.
Figure 5 : Scanning electron microscopy (SEM) views of vascular-like tissue structures and internal erythrocyte impressions (EN?) consistent in size and shape with mammalian RBCs.
Mammalian red blood cells are typically biconcave, anucleate, and highly flexible. These features are evident in multiple figures provided from the fossil sample archive. In contrast, non-mammalian RBCs—such as those from reptiles and birds—tend to be nucleated, oval, and less deformable. The observed fossilized structures do not resemble reptilian erythrocytes, which would be expected to retain nuclei in preserved form. Moreover, the concavity and discoidal shape of the arrowed specimens in several micrographs strongly resemble those of mammalian RBCs.
Some cells show evident deformation, implying elasticity—a hallmark of mammalian RBC cytoskeletal architecture. Their morphology also differs from that of potential microbial or diagenetic structures. This pattern, replicated across multiple samples and techniques (optical microscopy, SEM), strengthens the hypothesis that at least some dinosaurs could have had mammalian-type erythropoiesis.
Conclusion
The figures presented here—particularly those with round, concave, and anucleate cell morphologies—strongly support the interpretation that some dinosaurs possessed mammalian red blood cells. If validated by further chemical and ultrastructural analysis, this would have profound implications for dinosaur phylogeny and physiology, potentially requiring reclassification of certain clades closer to mammals than to reptiles or birds.
Wretch Fossil’s website:http://wretchfossil.blogspot.com/
Source: https://wretchfossil.blogspot.com/2025/09/evidence-for-mammalian-red-blood-cells.html
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world. Anyone can join. Anyone can contribute. Anyone can become informed about their world. "United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
LION'S MANE PRODUCT
Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules
Mushrooms are having a moment. One fabulous fungus in particular, lion’s mane, may help improve memory, depression and anxiety symptoms. They are also an excellent source of nutrients that show promise as a therapy for dementia, and other neurodegenerative diseases. If you’re living with anxiety or depression, you may be curious about all the therapy options out there — including the natural ones.Our Lion’s Mane WHOLE MIND Nootropic Blend has been formulated to utilize the potency of Lion’s mane but also include the benefits of four other Highly Beneficial Mushrooms. Synergistically, they work together to Build your health through improving cognitive function and immunity regardless of your age. Our Nootropic not only improves your Cognitive Function and Activates your Immune System, but it benefits growth of Essential Gut Flora, further enhancing your Vitality.
Our Formula includes: Lion’s Mane Mushrooms which Increase Brain Power through nerve growth, lessen anxiety, reduce depression, and improve concentration. Its an excellent adaptogen, promotes sleep and improves immunity. Shiitake Mushrooms which Fight cancer cells and infectious disease, boost the immune system, promotes brain function, and serves as a source of B vitamins. Maitake Mushrooms which regulate blood sugar levels of diabetics, reduce hypertension and boosts the immune system. Reishi Mushrooms which Fight inflammation, liver disease, fatigue, tumor growth and cancer. They Improve skin disorders and soothes digestive problems, stomach ulcers and leaky gut syndrome. Chaga Mushrooms which have anti-aging effects, boost immune function, improve stamina and athletic performance, even act as a natural aphrodisiac, fighting diabetes and improving liver function. Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules Today. Be 100% Satisfied or Receive a Full Money Back Guarantee. Order Yours Today by Following This Link.
| Visits: | 1,725,332,463 |
| Stories: | 8,489,972 |
Whistler Blowers, Insiders
