Re: Apatosaurus vs. Brontosaurus

[Ken Carpenter <KCarpenter@dmns.org>]

Having just gotten back from the field, I had to play catch-up regarding 
Apatosaurus and Brontosaurus. Apatosaurus ajax was named by Marsh in December 
1877 (YPM 1860) for a partial skeleton from Arthur Lake's quarry 10 near 
Morrison, Colorado. Brontosaurus excelsus was named by Marsh in December 1979 
(YPM 1880) for a partial skeleton from Walter Reed's quarry 10 at Como Bluff, 
Wyoming. Elmer Riggs (1903) concluded that Apatosaurus and Brontosaurus 
represented the same genus, noting that the differences were minor and due to 
the slightly younger nature of Apatosaurus. Because Apatosaurus was named 
several years earlier than Brontosaurus, he considered this the valid name. The 
origin of the name "Apatosaurus" (commonly interpreted to mean "deceptive 
lizard"), is unknown since Marsh does not give his reason. It may or may not 
have anything to do with the chevrons as was suggested. It is equally likely 
that it refers to weight of the animal being deceptively less than one might !
 assume
 from the large limb bones because of the pneumatic cavities in the cervicals 
as Marsh pointed out.  Brontosaurus as "thunder-lizard" is more apparent.

But why did the name Apatosaurus languish unknown to the general public so 
long? There are apparently several reasons. First, Marsh had presented a 
reconstruction of Brontosaurus (1883, revised 1891). This reconstruction in the 
American Journal of Science was readily available worldwide, and thus easily 
reproduced in books and magazines (e.g., K. Zittel 1902 Grundzuge der 
Palaeontologie) as Brontosaurus. Second, the pelvis and hindlimb of B. excelsus 
was mounted for public exhibit at the Peabody Museum in 1901, with signage 
calling it "Brontosaurus".  The first skeleton was mounted for exhibit at the 
American Museum of Natural History and completed in February 1905. Again the 
signage called the specimen "Brontosaurus." Why this name, rather than 
Apatosaurus was used at the AMNH is not given by Matthew ("The mounted skeleton 
of Brontosaurus" The American Museum Journal v. 5:63-70).  Nevertheless, the 
millions of museum visitors in subsequent years knew this large skeleton (he!
 nce, the
 living animal) as Brontosaurus. Not until more recent years has there been an 
attempt by dinosaur paleontologists to educate the public as to the correct 
name Apatosaurus.

Finally, there is the matter of the skull. The skull that Marsh used to 
complete his reconstruction was described by Virginia Tidwell and me as 
Brachiosaurus (USNM 5730; 1998, Modern Geology 23:69-84). In many ways, this 
skull does look camarasaurid, hence for many years "Brontosaurus" was said to 
have the wrong, camarasaurid-like skull. Why did this happen? Most likely it is 
because Marsh was greatly influenced by M.P. Felch who excavated the skull. 
Felch wrote to Marsh (June 4, 1884), "The cervical vertebrae mentioned in my 
last [letter] are Brontosaurus as you have figured them - and from their 
position - skull No. 2 [USNM 5730] must have belonged with them."  Marsh 
apparently agreed with Felch, thus felt justified in using this skull on 
reconstruction of a skeleton of Brontosaurus collected several hundred miles 
away.  It certainly made a lot of sense that the robust skeleton of 
Apatosaurus/Brontosaurus would have a robust, camarasaurid-like skull, rather 
delicate diplod!
 ocid
 skull that Holland later suggested. It is no wonder that he was reluctant to 
accept Osborn's challenge to mount the diplodocid-like skull on the Carnegie 
Museum Apatosaurus.

Kenneth Carpenter, Ph.D.
Curator of Lower Vertebrate Paleontology &
Chief Preparator
Dept. of Earth Sciences
Denver Museum of Natural History 
2001 Colorado Blvd.
Denver, CO 80205

Phone: (303)370-6392
Fax: (303)331-6492
email: KCarpenter@DMNS.org

For fun:
 http://dino.lm.com/artists/display.php?name=Kcarpenter


>>> "Wilson, Yvonne" <WilsonY@CarnegieMNH.Org> 25/May/04 >>>

Dan Varner wrote,
"It wasn't Marsh Holland was worried about, ... It was Henry Fairfield
Osborn "

I didn't mean Marsh himself, but rather his work, but I was still wrong.
Thanks for the clarification.  Unfortunately much of the historical
knowledge here is passed by word of mouth, which isn't always the best means
of transmission.

Where did you read the original correspondence?  I would be quite interested
in seeing it.  (Chances are it's in the basement here at the Carnegie,
right?)




Happy Tuesday to All,
Yvonne


Yvonne M. Wilson
Division of Education
Carnegie Museum of Natural History
4400 Forbes Avenue
Pittsburgh, PA  15213
412-578-2456