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Robert Feranec Curator of Vertebrate Paleontology, NYSM

TOTALLY AWESOME: Extreme Evolution in Mammals—YEAH!! (with fist pump). Robert Feranec Curator of Vertebrate Paleontology, NYSM. EXTREME!!!. Who’s the Biggest?. Who’s the Smallest?. Who’s the Baddest?. Best Common Name?. Best Scientific Name?. Who’s the Biggest?: Paraceratherium.

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Robert Feranec Curator of Vertebrate Paleontology, NYSM

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  1. TOTALLY AWESOME: Extreme Evolution in Mammals—YEAH!! (with fist pump) Robert Feranec Curator of Vertebrate Paleontology, NYSM

  2. EXTREME!!! Who’s the Biggest? Who’s the Smallest? Who’s the Baddest? Best Common Name? Best Scientific Name?

  3. Who’s the Biggest?: Paraceratherium EXTREME!!! • Age: 30 million years ago • Height: upto 23 feet tall (15 feet at shoulder) • Weight: upto 20 tons

  4. Who’s the Smallest?: Batodonoides EXTREME!!! • Age: 53 million years ago • Height: small • Weight: 1.3 grams

  5. Best Scientific Name?: Sunkahetanka pahinsintewakpa EXTREME!!! Hesperocyonidae (distant canid relative) • Age: 28 million years ago • Weight: 20 kgs

  6. Best Common Name?: Gunther’s Dik Dik EXTREME!!! • Age: Modern • Height: upto 40 cm • Weight: upto 5 kgs

  7. EXTREME?

  8. Head Gear EXTREME!!!

  9. Why Head Gear? EXTREME!!! Defense: Combat: Mate Recognition: Ornamentation:

  10. Natural Selection EXTREME!!! Differential survival and reproduction

  11. Sexual Selection EXTREME!!! Certain evolutionary traits are the result of intraspecific competition Intrasexual Competition: Generally Male-Male competition, female mates with the “winner” Intersexual Competition: Female Choice

  12. Types of Head Gear? EXTREME!!! Ossicones: Horns: Antlers: Pronghorns:

  13. Head Gear: Ossicones EXTREME!!!

  14. Head Gear: Ossicones Fossils EXTREME!!! Samotherium ~4 million years ago Sivatherium ~8,000 years ago

  15. Head Gear: Horns EXTREME!!!

  16. Head Gear: Horns Fossils EXTREME!!! Synthetoceras Syndoceras Hoplitomeryx Bison latifrons Cranioceras

  17. Head Gear: Horns Fossils EXTREME!!! Arsinoitherium (from Egypt) Age: 35 Ma Height: ~7 feet at shoulder

  18. Head Gear: Horns Fossils EXTREME!!!

  19. Head Gear: Horns Fossils: Brontotheriidae EXTREME!!!

  20. Mylagaulid rodentsWhy do they have those crazy horns? EXTREME!!! 30-5 Ma North America

  21. Mylagaulid Ecology EXTREME!!! • Herbivorous • Body size: ~ 0.5-5 kg. • Fossorial (burrowing), but how? • One of the only fossorial animals with horns Millions of years ago

  22. Fossorial adaptation in rodents EXTREME!!! Scratch digging Chisel tooth digging Head lift digging Figure from Stein 2000

  23. Head digging in mylagaulids EXTREME!!! Features consistent with head-digging: • Thickened, projecting nasal bones • Tall, forward-tilted occipital plate • Shortened skull • Powerful forelimbs Likely evolved from head-lift diggers

  24. Why horns? EXTREME!!! Possible uses of horns: • Species recognition • Digging • Sexual display/combat • Defense

  25. Horns : digging implement EXTREME!!! In favor: • Higher occipital plate with taller horns Against: • Position, orientation of horns • Change in horns through time • Increases force needed to dig • CONCLUSION: unlikely

  26. Horns : sexual display/combat EXTREME!!! • Not sexually dimorphic • Lack of visual ability • Display useless underground • Orientation of horns • CONCLUSION: unlikely

  27. Horns : defense EXTREME!!! • Passive or active defense • Predator diversity: mustelids (weasels and stoats), snakes? • CONCLUSION: Likely, consistent with available evidence.

  28. Horns…or Not Horns EXTREME!!! Coelodonta Late Pleistocene (~20,000 years ago) Europe

  29. EXTREME!!! NOT “true” horns Coelodonta Late Pleistocene (~20,000 years ago) Europe

  30. Horns…or Not Horns EXTREME!!!

  31. EXTREME!!! Horns

  32. Horns…or Not Horns EXTREME!!! Narwhal (modern)

  33. EXTREME!!! NOT Horns

  34. Head Gear: Pronghorns EXTREME!!! Antilocapra americana

  35. Head Gear: Pronghorns Fossils EXTREME!!! Ramoceros 12 Mya Ilingoceros 8 Mya Merycodus 15 Mya

  36. Head Gear: Antlers EXTREME!!!

  37. Head Gear: Antlers EXTREME!!!

  38. Head Gear: Antlers Fossils EXTREME!!! Megaloceros giganteus ~10000 years ago • Each antler is 6ft long

  39. Antlers and… EXTREME!!!

  40. Antlers and… Saberteeth!!! EXTREME!!! Moschus Modern

  41. Why Head Gear? EXTREME!!! Defense: Combat: Mate Recognition: Ornamentation:

  42. Evolution of saberteeth EXTREME!!! Machaeroides Eusmilus Smilodon Homotherium Thylacosmilus Machaerodus

  43. Eating! EXTREME!!! From Akersten 1985

  44. Is the evolution of the sabertooth convergent evolution or parallel evolution? Smilodon Homotherium

  45. Convergent Evolution vs. Parallel Evolution? Convergent Evolution: describes the acquisition of the same biological trait in unrelated lineages. Parallel Evolution: the development of a similar trait in different not closely related species (that is in species of a different clade), but descending from the same ancestor.

  46. Question: How do we distinguish how closely an organism is related? How to Solve this? Hall (2003) Biological Reviews

  47. Question: How do we distinguish how closely an organism is related? How to Solve this? Convergence: Similarity arising through independent evolution having different developmental pathways Parallelism: A feature present in closely related organisms but not present continuously in all members of the lineage, and uses similar developmental pathways. Hall (2003) Biological Reviews

  48. Evolution of saberteeth EXTREME!!! How do they develop? Thylacosmilus Machaerodus

  49. You are what you eat…and drink

  50. Oxygen Isotopes (Isotope: same # of P, E- but different # of N) Isotopes in modern precipitation FLAGSTAFF, AZ 1961-1963 +d18O d18OSMOW -d18O August January January From IAEA GNIP Database

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