Monday, February 28, 2022

Is Tyrannosaurus rex really 3 species?

 We've all grown up knowing a T. rex is a T. rex, and that's all there is to it.  A study published in the journal Evolutionary Biology suggests otherwise, According to the authors, there are three species.  Three times the Tyrannosaur goodness?  
After looking over the existing specimens of T. rex (there are only 38 in the world, according to one count) Paleontologist Gregory Paul and his coauthors believe they fall into three body types different enough from each other to be named species. He proposes we add T. imperator (emperor), and T. regina (queen), The world's most famous fossil skeleton, the Tyrannosaurus "Sue" in the Field Museum, is named as the type specimen for T. imperator. 
Some paleontologists were disappointed by the paper because there had been so much hype preceding it.  They expected a major discovery based on new fossils, not an argument for reclassification.  
This new royal family has sparked immediate controversy. We think of paleontologists as a serious lot, if not actually dull, but the debate in this case, while professional, is already getting fierce.  Dr. Steve Brusatte, author of the  superb popular book The Rise and Fall of the Dinosaurs (2018), thinks the differences cited are "...very minor and not indicative of meaningful biological separation of distinct species,,," PaleoTwitter, which is a VERY active community with a lot of calm professional discourse sprinkled with non-calm acrimonious discourse, is abuzz, and most of the buzz ia about how the paper is wrong.  But t
he storm of prehistoric dust is just starting. Many debates and studies lie ahead. Consensus may never come.  
NOTE: Dr. Alan Grant could not be reached for comment.
One vision of T. rex (public domain) 

Congratulations to Tetrapod Zoology

Congratulations to Dr. Darren Naish, whose blog Tetrapod Zoology marked its 16th birthday. Darren is a paleontologist who, among many other accomplishments, revolutionized our view of the largest pterosaurs. The blog offers posts about countless vertebrates, living or extinct, along a friendly skeptic's takes on the cryptozoological world.

Wednesday, February 09, 2022

What did Megalodon Look Like?

 New study conclusions

Body forms of extant lamniform sharks (Elasmobranchii: Lamniformes), and comments on the morphology of the extinct megatooth shark, Otodus megalodon, and the evolution of lamniform thermophysiology

Phillip C. Sternes, Jake J. Wood & Kenshu Shimada

One proposed comparison shape (marked "Free to Use and Share' on Creative Commons)

This is a really good example of what we can and can't know from incomplete fossils. Sharks, like my favorite fish
, have a cartilaginous skeletons that rarely fossilize.  

Did they look like great whites? Did they look more like some other extant shark? 

We don't know. 

"...all previously proposed body forms for O. megalodon should be regarded as speculations (Figure 9) because there are no scientific means to decisively support or refute the accuracy of any of them. Any meaningful discussion on this specific topic would require the discovery of much better-preserved fossil specimens than what are presently known in the fossil record of O. megalodon."


Monday, February 07, 2022

Black History Month: the Astronauts

NASA's first three Black astronauts were picked in January 1978 as part of the first Shuttle program group of 35 astronauts. NASA had expanded the criteria for this group: all previous astronauts had to be test pilots, meaning the pool for Mercury through Apollo (which expanded the rule just a bit to allow scientists, with geologist Harrison Schmidt reaching the moon on Apollo 17), consisted almost entirely of white males.  The TFNG (Thirty-Five New Guys) also included the first American women. 

The first Black astronaut to fly was Air Force pilot Guion Bluford in 1983. (I met him 15 years later, when he was a VP at engineering services firm NYMA. He was a reserved fellow, the kind who didn't need to command attention as astronauts (and, by legend, all military pilots), sometimes do. Physicist Ron McNair first flew in 1984 and  died in the Challenger disaster in 1986. Air Force pilot Fred Gregory flew in 1985 and became become the first Black American to pilot, and later command, a space vehicle.  He became the NASA Deputy Administrator, at one point serving two months as the Acting Administrator.  A little-known fact is that he was the nephew of the famous physician, Dr. Charles Drew. Marine pilot Charles Bolden, selected in the next group in 1980, became the first permanent Black NASA Administrator.  One other Black astronaut has given his life for exploration: payload commander Michael Anderson, another Air Force officer, was on the shuttle Columbia on February 1, 2003.


Major Robert Lawrence, picked in 1967 by the Air Force for the to-be-canceled Manned Orbiting Laboratory (MOL), would likely have transferred to NASA and eventually flown the Shuttle had he not died in a crash a few months after his selection.


Captain Edward Dwight, Jr. was an Air Force pilot added as a candidate in 1963 from outside the usual process – JFK himself picked him to integrate the program - but he was still in the test pilot qualification program when selected, and he never did make the cut for selection by NASA.


The first person of African descent to reach space was Afro-Cuban cosmonaut Arnaldo Tamayo Mendez, who flew on Russia's Soyuz 38, orbiting on September 18, 1980.

Photographs (Dwight and Lawrence photos USAF, others NASA)

Bluford, McNair, and Gregory in 1978





Bolden (as NASA Administrator, 2009)

Gregory (as NASA Acting Administrator in 2005)