WHALES HAVE HANDS

WHALES HAVE HANDS AND THEIR BLOWHOLES ARE JUST HIGHLY MODIFIED NOSES THE EVOLUTION OF WHALES HARD TO BELIEVE THE TRANSITION IS BEST DOCUMENTED CHANGES IN THE FOSSIL RECORD SO IN THIS TO BREAK DOWN 53 MILLION YEARS OF EVOLUTION HOW THIS TURNED INTO SOMETHING LIKE THAT EVERYTHING I SAY COMES FROM THIS PAPER THAT WAS JUST PUBLISHED REVIEW OF WHAT WE KNOW ABOUT THE EVOLUTION OF PUBLISHED BY DR. TRAVIS PARK Land to water transition EOCENE ORIGINS THE EVOLUTION AND diversification of Cetacea Abstract Ceteceans, that is, whales, dolphins and porpoises, have rightfully been deemed a prime example of macroevolution. Few other animal groups document such radical morphological change in their fossil record, culminating in a wide range of extant morphological and phylogenetic diversity. This diversity has spurred intensive study of the clade, with advances in quantitative methods since the turn of the century facilitating new insights into cetacean evolutionary dynamics. The story of cetacean evolution is now more detailed than ever before, from terrestrial origins at the river's edge in early Eocene Indo-Pakistan to their modern role at the apex of marine ecosystems. This story has the power to inform scientists on how living species will fare in the face of unprecedented ecological change. In this Review, I provide a summary of cetacean macroevolutionary patterns and the factors that have influenced their evolutionary history. Despite understanding of this enigmatic group, many questions remain. Here, I outline some key areas that should focus future research. No external ear External ear visible Forelimbs Hindlimbs Thin tail No tail fluke No external ear Flippers Loss of hindlimbs Muscular tail Tail fluke Nostrils at the end of snout Nostrils on head THE EVOLUTION OF WHALES PUBLISHED BY DR. TRAVIS PARK I mentioned earlier that the earliest PROTO WHALES THE EARLIEST CETACEANS ARE AROUND 53 MILLION YEARS OLD BUT THE STORY ACTUALLY STARTS 66 MILLION YEARS AGO WHEN THE ASTEROID HITS EARTH NON-BIRD DINOSAURS LIKE TRICERATOPS AND T-REX GO EXTINCT THE PTEROSAURS DOMINATING THE SKIES GO EXTINCT THE MOSASAURS AND PLESIOSAURS THE REPTILES THAT HAVE BEEN DOMINATING THE OCEANS TOO THAT LEAVES FREE REAL ESTATE AN OPEN NICHE TO ANY GROUP TAKE ADVANTAGE OF THAT OCEAN FIRST AND WHAT WE ANCESTORS OF WHALES IN A SPECIFIC REGION WHICH IS NOT CONNECTED TO ANY OTHER LANDMASSES AT THIS TIME A LARGE ISLAND WITH LOTS OF COASTLINE LOTS OF RIVERS LOTS OF WET AREAS A GROUP OF MAMMALS START THRIVING IN THAT WETTER IN SCHOOL YOU PROBABLY HEAR OF PAKICETUS THE LITTLE DOG WAS HUNTING IN THESE RIVER ECOSYSTEMS WE NOW KNOW AN EVEN OLDER PROTOCETACEAN KALAKOCETUS A RACCOON SIZED ONE THEY'RE ESSENTIALLY LITTLE MAMMALS TAKING ADVANTAGE OF THESE RIVER ECOSYSTEMS THE PAKICETIDS CONTINUE HUNTING THOSE RIVER ECOSYSTEMS BUT WITHIN FIVE SEE ANOTHER GROUP START TO EMERGE THAT IS THE AMBULOCETIDS ISLAND AT THIS IMPORTANT TO REMEMBER THE WHALE LINEAGE IS ESSENTIALLY EMERGING IN ISOLATION ON THIS ISLAND EVENTUALLY START TO THE REST OF Rudolf Hima THE REST OF THE WORLD BUT THAT WASN'T THE AMBULOCETIDS INSTEAD IT'S THE REMI NGTONOCETIDS WHICH ARE CLOSE COUSINS OF THOSE AMBULOCETIDS BUT THEY SEEM TO BE MORE ADAPTED FOR THE AQUATIC LIFESTYLE AS FAR AS WE KNOW THE FIRST GROUP OF ANCIENT WHALES TO LEAVE THAT TECTONIC PLATE REGION AND CROSS THE OCEAN YOU LOOK AT THE EARLY EOCENE WE HAVE ANCIENT WHALES IN ONE SINGULAR LOCATION MIDDLE EOCENE YOU CAN SEE THESE PROTOCETIDS THIS REALLY DIVERSE GROUP THEY HAVE SPREAD OUT BY 43 SO WITHIN FIVE MILLION YEARS OF REALLY TAKING OVER THE OCEANS A NEW DOMINANT GROUP THE BASILOSAURIDS THIS GROUP IS ANCESTRAL WHALES IT'S THE FIRST THROUGH GIGANTISM WHERE WE SEE THE LOSS OF THAT PELVIS AND HIGHLIMB CONNECTEDNESS THE OCEANS OVER THE NEXT FIVE SO ARE DOMINATED BY THE BASILOSAURIDS THE SEMIAQUATIC COUSINS ALL GO EXTINCT ACROSS THIS TIME AND THEN 39 MILLION YEARS AGO A NEW GROUP EMERGES FROM THE BASILOSAURIDS IS ABLE TO TAKE ADVANTAGE OF THE DEEPER REGIONS FURTHER FROM THE COAST BASILOSAURIDS STILL DOMINATE THE COASTAL REGIONS From Greenhouse to Icehouse THE MARINE EOCENE-OLIGOCENE TRANSITION WE SEE THE COASTLINE START TO SHIFT AND THE BASILOSAURIDS PART GO EXTINCT IT'S WORTH MENTIONING THIS ISN'T INSTANTANEOUS WHILE MOST OF THE BASILOSAURIDS GO EXTINCT DURING THAT TRANSITION THEY HUNG ON FOR MILLIONS OF YEARS OF NEW ZEALAND THIS IS ALSO RECORD STARTS TO GET MORE FRAGMENTARY BECAUSE NOW THE REMAINING CETACEANS ARE ALL LIVING FURTHER FROM THE COAST THEY'RE LESS LIKELY TO FOSSILIZE AND BE FOUND BY Miocene climate and crown clade cetaceans The diversification of crown Neoceti The drop in sea levels around the globe associated with the Oligocene- Miocene transition appears to have initiated a turnover event in the contemporary cetacean fauna, with archaic nearshore lineages going extinct (Fig. 2). These conditions were resulted in relatively few cetacean fossils being discovered from the earliest Miocene. The fossil record is particularly poor for baleen whales around this time, with the only definitive fossils found so far coming from New Zealand. The offshore habitat of these animals, now all baleen-bearing, also probably reduced their preservation rate. Despite a lack of diagnostic fossils, phylogenetic studies indicate that balenids and plicoguligans began to diversify and expand their ranges during the earliest Miocene. Nevertheless, the Miocene proved to be a single major extinction period in cetacean history. I'VE ALSO GOT THE LATE MIOCENE ALSO SAW THE APPEARANCE OF PERHAPS THE MOST UNUSUAL CETACEAN FOSSILS YET FOUND, ODobenocetops, a delphinoid which convergenly evolved remarkable similarities to walruses, as well as losing its ability to echolocate. Now around 3.2 MILLION YEARS AGO IS WHEN MEGALODON AND MEGALODON GOES EXTINCT FACT THAT THE EARTH IS GOING INTO AN ICE AGE AND THAT ICE WAS NOT GREAT FOR WHALES EITHER LINEAGES WERE LOST OVER THE LAST SOME MADE IT CLOSER TO THE MODERN DAY THAN BUT THIS IS ESSENTIALLY THE TIME THAT LEAVES US WITH OUR MODERN WHALE BIODIVERSITY THAT INTERESTING AND MORE ABOUT EVOLUTION MAKE SURE TO AS I CAN - IT WAS REALLY THE WHALE STORY THAT GOT ME EVOLUTION IN THE FIRST PLACE