Did Dinosaurs Have Belly Buttons?

TL;DR

Belly buttons, or umbilical scars, are not exclusive to humans, with various animals, including dinosaurs, also having them.

Transcript

I don’t know about you,  but I love my belly button. It’s an adorable reminder that I spent  about nine months inside another human, leeching off their body until  I was big and strong enough to get nutrients down my own mouth hole. You know, instead of the fleshy  straw sticking out of my tummy. But while human belly  buttons are pretty prominent,... Read More

Key Insights

• ⏺️ Belly buttons are the remnants of the umbilical cord, present in various species.
• 🈸 Placental mammals, such as humans, dogs, and cats, have visible belly buttons.
• 😨 Viviparous sharks and egg-laying amniotes, including birds and reptiles, also have umbilical scars.
• 🥶 The oldest known belly button belongs to a Psittacosaurus dinosaur, preserved in a 130 million-year-old fossil.
• 🔄 Laser-stimulated fluorescence imaging was used to identify the Psittacosaurus belly button.
• 🦕 Belly buttons may have been retained throughout the lives of Psittacosaurus dinosaurs.
• 🐦 Belly buttons in modern dinosaurs, birds, can be difficult to find.

Questions & Answers

Q: Do all animals with umbilical scars keep them for life?

While it is uncertain for most species, it is possible that Psittacosaurus dinosaurs, like humans, retained their belly buttons throughout their lives, although not all adult dinosaurs likely had belly buttons.

Q: How do we know that dinosaurs had belly buttons?

Scientists used an imaging technique called laser-stimulated fluorescence to capture images of the Psittacosaurus fossil, revealing a raised ridge where the umbilicus would be. This method was also used on present-day birds and reptiles, showing similar scarring.

Q: Can we find belly buttons on modern dinosaurs?

Modern dinosaurs, known as birds, can have belly buttons, but they are challenging to find. The Psittacosaurus fossil is one of the rare cases where a belly button was discovered.

Q: How do viviparous sharks have belly buttons?

Viviparous sharks, such as hammerheads or lemon sharks, develop a quasi-umbilical cord to attach themselves to their mother's uterine wall until they are ready to be born. The resulting belly button fades over time but can be seen in young sharks.

Summary & Key Takeaways

• Belly buttons are the remnants of the umbilical cord and are present in many species, not just humans.

• Mammals, birds, reptiles, and even some sharks have umbilical scars.

• The oldest known belly button belongs to a Psittacosaurus dinosaur, preserved in fossil remains.