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Ontogeny

All articles tagged with #ontogeny

Tiny to towering: Montana Troodon fossils reveal full growth from embryo to adult
paleontology1 month ago

Tiny to towering: Montana Troodon fossils reveal full growth from embryo to adult

New Montana Troodon formosus fossils provide a near-complete record of pelvic and hindlimb ontogeny from embryo to adult, revealing mostly consistent bone shapes across growth with stage-specific changes in bone strength, texture, and fusion; the femur lengthens relative to the tibia in adults, indicating steady growth. The sample also shows adult size variation and common foot pathologies, and it underpins a proposed taxonomic shift away from a tooth-based type specimen to pelvic/hindlimb fossils, pending ICZN approval. Together, the findings illuminate locomotion and life history in troodontids.

Great White Sharks Reveal a Lifetime of Teeth Transformation
science8 months ago

Great White Sharks Reveal a Lifetime of Teeth Transformation

Researchers examined nearly 100 great white sharks and found that tooth shape changes dramatically along the jaw and as sharks grow. Juvenile teeth are slim with cusplets for gripping small prey; around 3 meters in length they become broader, thicker, and serrated, while cusplets disappear. Lower teeth grab and hold prey, upper teeth slice and dismember, forming a coordinated feeding system. Teeth are constantly replaced, letting the bite reflect a shark’s dietary shift from fish and squid to marine mammals as it matures; the study provides a jaw-wide view of dental evolution across development.