redheaded stepsiblings

[01101]

The only definition I could find for redheaded was a person with red hair, but I'm not sure why he would refer to the invertebrate paleontologists as redheaded in this sense. Any suggestions?

I was a bit embarrassed to realize that invertebrate paleontologists—our redheaded stepsiblings, who study fossils like clams and corals, which don’t have bones—had come up with a method two decades earlier, one that had been ignored by dinosaur workers. It was something called morphological disparity.

Source: The Rise and Fall of the Dinosaurs: A New History of a Lost World by Steve Brusatte.

 

[dojibear]

Here the "we" ("our") probably means "vertebrate paleontologists". So he is saying that invertebrate paleontologists are the redheaded stepsiblings of us vertebrate paleontologists.

Literally "redheaded stepsiblings" means people who have one different parent (either mother or father has remarried) with different hair color. The difference in hair color points out their difference, even though they are related.

Figuratively it means people who are different, but related. It often means people who are "less important" or "less popular" but related. In this case scientists who study invertebrate fossils get less attention than scientists who study dinosaur fossils.

 

[kentix]

red-head·ed step·child

noun
INFORMAL•US

1. a person or thing that is neglected, unwanted, or mistreated.
   "audio has always been something of a red-headed stepchild in the PC world"

In your example they have changed the standard form a bit but it's the same meaning. Redheads are less common than blondes and brunettes and have sometimes been looked down on and made fun of when they were kids. So the idea is that redheads get less respect than others. The same has sometimes been true with step-children. They have gotten less respect than other children in families sometimes.

Calling something a red-headed stepchild means it gets less respect than other similar things that it theoretically should be equal to. Others look down on it.

So he is saying that people who study vertebrates get more scientific respect than people who study invertebrates. The people who study invertebrates get ignored so much that even when they made an important discovery, none of the vertebrate paleontologists noticed for 20 years.