Just from my geology course work in college:
The half life of Carbon 14 is approximately 5700 years, and the maximum useful date that can be derived from Carbon dating is about 40,000-50,000 years. Some paleontologists have claimed that it can date things as much as 60,000 or 70,000 years, but that is mere speculation. It can't possibly be used to date something to 1.8 million years.
The dating material that would be most likely to be able to show an age of a million years is potassium-argon dating, but that, like other radio-isotope methods, can only be done using igneous or some metamorphic rocks. But every fossil is found in sedimentary rocks, not igneous or metamorphic rocks, so it requires quite a bit of real geology work for any of those dating methods to determine (really an educated guess) an age for any fossil.
That's why you should be skeptical of every date that is given for any fossil; it's based on many unspoken assumptions that have more to do with imaginations than facts.
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