Betwixt The Sheets: The History of Sex, Scandal & Society
Episode: How Did Dinosaurs Have Sex?
Release Date: January 24, 2025

Host: Kate Lister
Guest: Dr. David Hone, Paleontologist from Queen Mary's University, London

1. Introduction to the Episode

In this intriguing episode of Betwixt The Sheets, host Kate Lister delves into a fascinating and unconventional topic: "How Did Dinosaurs Have Sex?" Joined by expert paleontologist Dr. David Hone, the discussion navigates the complexities of dinosaur reproductive behaviors and anatomy, shedding light on behaviors that prehistoric creatures might have exhibited millions of years ago.

2. Guest Introduction

Kate introduces Dr. David Hone, a seasoned paleontologist specializing in non-avian dinosaurs and pterosaurs. Dr. Hone brings a wealth of knowledge to the conversation, offering insights into dinosaur physiology and the challenges scientists face in reconstructing their mating behaviors.

Kate Lister [05:20]: "Hello and welcome to Betwixt the Sheets. It's only Dave Hone. How are you doing?"
Dr. David Hone [05:25]: "All right, thank you. Teaching is finished for the year, so that always puts me in a slightly better mood."

3. Dinosaur Classification and Timescale

Dr. Hone begins by clarifying the classification of dinosaurs, emphasizing the distinction between non-avian dinosaurs and their avian descendants, the birds.

Dr. Hone [06:23]: "So I work on non-avian dinosaurs and some other groups as well. I also do quite a lot on pterosaurs, the flying reptiles that are also not dinosaurs that lived alongside them."

He highlights the extensive timescale during which dinosaurs thrived—approximately 180 million years—and contrasts this with the relatively brief existence of humans in geological terms.

Dr. Hone [07:15]: "The oldest dinosaurs are somewhere around 230ish million years old. And then they go extinct 65.5 million years ago."

4. Reproductive Anatomy of Dinosaurs

Lister probes into the fundamental question of dinosaur reproduction, questioning the mechanisms behind their mating given their diverse and often peculiar anatomies.

Kate Lister [10:22]: "They are very, very successful. And one of the ways that they are able to be successful is they must have been having sex. What kind of sex were dinosaurs have it?"

Dr. Hone discusses the inevitability of sexual reproduction among dinosaurs, given their prolonged existence and the vast number of species that emerged during their reign.

Dr. Hone [11:10]: "Dinosaurs must have had sex, otherwise there wouldn't have been little dinosaurs, certainly not for a very long period of time."

He explains that as amniotes, dinosaurs engaged in internal fertilization, a reproductive strategy shared with reptiles, birds, and mammals.

5. Challenges in Understanding Dinosaur Mating

The conversation delves into the inherent difficulties in deciphering dinosaur mating behaviors from fossil records, primarily because soft tissues rarely fossilize.

Dr. Hone [13:50]: "We really can't say very much at all beyond the fact that almost certainly all of them were doing it."

Lister humorously addresses the speculative nature of reconstructing dinosaur mating positions and anatomies.

Kate Lister [22:42]: "How are they having sex? They can't even grab onto each other's hair with that. Like what are they doing?"

Dr. Hone emphasizes the reliance on osteological correlates—bone structures that can hint at soft tissue arrangements—to infer possible mating behaviors.

6. Specific Dinosaur Features and Their Role in Mating

A significant portion of the discussion centers around specific dinosaur traits, such as the Tyrannosaurus rex's diminutive arms and the elaborate frills of Ceratopsians like Triceratops.

Dr. Hone [22:22]: "The really big sauropod, so the long neck, long tailed diplodocus... getting them together is going to be interesting."

He explores theories about how physical attributes influenced mating strategies, suggesting that features like the T. rex's arms were likely not involved in mating but served other purposes.

7. Mating Rituals Evidenced by Fossil Footprints

One of the most compelling parts of the episode is the analysis of dinosaur footprint sites that hint at possible mating rituals.

Dr. Hone [27:10]: "The really short version of this is what they have is its footprint. So it's a whole bunch of track sites where what you have is two sets of pairs..."

He describes scenarios where paired furrows in fossilized footprints suggest face-to-face interactions, potentially indicative of mating dances or rituals.

Dr. Hone [29:26]: "They line up face to face and the males and females do a little nod and a little dance and then they scrape with the left foot and then the right foot..."

Dr. Hone draws parallels between these fossilized behaviors and modern bird rituals, strengthening the case for such interpretations.

8. Sexual Selection in Dinosaurs

The discussion transitions into the concept of sexual selection, using Ceratopsians as a primary example. Dr. Hone explains how features like the frills of Protoceratops evolved as sexual signals.

Dr. Hone [31:26]: "Protoceratops... has this really big frill which all the Ceratopsians, or nearly all the ceratopsians have. And this has been the subject of arguments for years, basically exactly what was it for?"

He presents evidence showing that the growth patterns of these frills correlate with the ages of sexual maturity, suggesting their role in mating displays.

Dr. Hone [34:11]: "You can measure how big they are and then measure how big their frill is and compare the two. And lo and behold, the growth curve of the frill... it suddenly grows much faster."

9. Monogamy and Mating Behaviors

Lister raises the topic of monogamy, questioning whether dinosaurs exhibited such behaviors.

Kate Lister [37:39]: "In the animal world, true monogamy is actually incredibly rare... What do you think? Were dinosaurs monogamous?"

Dr. Hone asserts that monogamy was likely uncommon among dinosaurs, drawing parallels with modern species where even ostensibly monogamous animals often engage in infidelity.

Dr. Hone [37:51]: "Almost certainly not, because as you say, even supposedly monogamous things often cheat."

He introduces the idea of mutual sexual selection, where both males and females develop ornamentations to attract each other, citing examples from birds and other animals that mirror such behaviors.

10. Final Thoughts and Questions

In a lighthearted finale, Kate poses a playful yet scientific question about whether dinosaurs experienced orgasms.

Kate Lister [41:26]: "Do you think dinosaurs had orgasms?"

Dr. Hone acknowledges the speculative nature of this query, noting the lack of evidence in both dinosaurs and their modern relatives outside of certain mammals.

Dr. Hone [42:03]: "I'm not aware that birds or reptiles do... I'm just wondering what the payoff is for dinosaurs. If they had pleasure."

Concluding the episode, Dr. Hone provides listeners with resources to further explore his work and the fascinating world of dinosaur paleontology.

Dr. Hone [42:21]: "Davehoden.co.uk is my central website... I have a podcast called Terrible Lizards... I write for the Guardian occasionally."

Notable Quotes and Attributions

• Dr. Hone on Dinosaur Success:
  "Dinosaurs must have had sex, otherwise there wouldn't have been little dinosaurs, certainly not for a very long period of time."
  (11:10)

• Dr. Hone on T. Rex Arms:
  "A T Rex's arm is about the same size and proportion as mine... So let's just rule that out."
  (22:42)

• Dr. Hone on Mating Ritual Footprints:
  "This is two animals face to face and they're bipeds. So they kind of do a little dance... and you'll end up with two pairs of furrows."
  (27:10)

• Dr. Hone on Sexual Selection:
  "If you're a female, you're putting a lot of effort into your eggs... So you want to advertise for the best male... What happens is they both end up with signaling structures to signal to each other."
  (40:48)

Conclusion

This episode of Betwixt The Sheets offers a captivating exploration into the reproductive lives of dinosaurs, blending scientific rigor with engaging storytelling. Through Dr. David Hone's expertise, listeners gain a deeper understanding of how these prehistoric giants may have navigated the complexities of mating, despite the limitations of the fossil record. From the physical challenges posed by their diverse anatomies to the evolutionary pressures shaping their mating behaviors, the episode paints a vivid picture of dinosaur sexuality, inviting listeners to ponder how these ancient creatures ensured their legacy through reproduction.

For those intrigued by the intersection of paleontology and sexual history, this episode provides both enlightenment and entertainment, demonstrating that even millions of years ago, the quest for reproduction was a driving force in the natural world.