Episode 351 is all about Linhenykus, the only non-avian dinosaur with a single finger.
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In this episode, we discuss:
News:
- A new unenlagiine raptor, Ypupiara, was found in Brazil with jaws that appear to be specialized for eating fish source
- Freeway construction in In São Paulo, Brazil uncovered a potential titanosaur claw in a cliff source
- The India Seashell Museum has a new Dinosaur Museum source
- Binder Park’s children’s zoo in Michigan, got a grant to build a “Zoorassic Park” of dinosaur sculptures source
- A 13,000 pound concrete minigolf T. rex sculpture was purchased for $11 in Milwaukee, Wisconsin source
- “Brickosaurs” were on display in Croydon, London made from half a million toy bricks source
- In Turkey a 150,000 balloon sculpture included several dinosaurs and set a Guinness World Record source
- Looper published a list of bizarre dinosaur movies source
The dinosaur of the day: Linhenykus
- Alvarezsaurid theropod that lived in the Late Cretaceous in what is now Inner Mongolia, China (Wulansuhai Formation)
- Pretty cute, had short arms, long legs and tail, and an elongated head
- Body type similar to Gallimimus (but much smaller, and with only the one finger on each hand)
- Small, with a 2.8 in (7 cm) long femur
- Estimated to weigh about 1 lb (450 g), about the same as a parrot
- Described in 2011 by Xing xu and others
- Found a partial skeleton, including forelimb, part of the pelvis, vertebral column, nearly complete hind limbs
- Type species is Linhenykus monodactylus
- Genus name means “Linhe claw”
- Genus name refers to Linhe, the city near where the fossil was found
- Species name means “single finger”
- Refers to it being the “only known functionally monodactyl nonavian dinosaur”, according to the original paper
- First known alvarezsaurid to have only the one digit (the second digit, specifically)
- Other alvarezsaurids have a large second digit and very short third and fourth digits (couldn’t use the outer fingers for anything)
- Had a reduced third metacarpal (connects wrist to fingers) but no finger bones (tapers off and was too small to support a finger)
- No fourth metacarpal found, but since the third metacarpal is so short and did not have finger bones, Linhenykus probably didn’t have a fourth metacarpal
- Most basal parvicursorine, a subfamily with large second digits
- Shows mosaic evolution in alvarezsauroid hands, since later alvarezsaurids had more digits
- Helps show the complexity of theropod hand evolution (theropods started with five fingers, then three, then two, like T. rex, and also one)
- May have eaten insects, and used its claws to dig around ant and termite nests
- Palms faced down, so that would help with digging
- Gareth Dyke and Darren Naish in 2011 questioned the paper, about how it did not really include European alvarezsauroids, and also suggested Linhenykus was not distinct enough to be different from Parvicursor, a similar, small dinosaur from Barun Goyot Formation named in 1996
- Said the only difference clear to them was “a slight discrepancy in size”
- Xing Xu et. al responded in 2011, and responded to all the points (basically didn’t agree and said Linhenykus had a number of features that made it distinct from Parvicursor, including some proportional differences, like Linhenykus having a longer metatarsal III than Parvicursor
- Also said Parvicursor had only been briefly described, and a more detailed comparison would probably show even more differences
- Other animals that lived around the same time and place included theropods, ankylosaurs, ceratopsians, small mammals, and lizards
Fun Fact: It’s possible to name a new dinosaur based on a holotype which has been lost or destroyed.
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