Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Total 8300; Flight Crew Type 340
Situational Awareness; Fatigue
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
This was the last leg of a 3 day trip with show times at or before 0500 local. While descending on the Ironman arrival into LAX; we were vectored off the arrival and instructed to descend to FL240 for traffic. Shortly after beginning the descent and turning to the assigned heading; we were cleared to a further fix on the arrival and told to resume the Ironman arrival.  Because we were lower than normal as a result of the early descent clearance; we discussed vertical navigation options and elected to do a 'vertical direct to' the assigned point. The non-flying pilot entered the 'vertical direct to' and we both went through the points in the FMS to ensure all projected crossing altitudes were within STAR restrictions and agreed that they were. In hindsight; I did notice that all the normally visible waypoint altitude depictions on my vertical profile went away but was either too busy or tired to question it. The aircraft intercepted its calculated descent profile and begin descending on profile. Shortly afterwards; a new ATC sector asked about our altitude and questioned our descent profile; instructing us to level at FL190 until intercepting the Ironman arrival. We quickly assessed the situation and reloaded the arrival to ensure everything was reset; then intercepted the new descent profile and continued without incident.Fatigue and complacency strike once again. As Flying Pilot; I should have been carefully comparing our actual altitude to the STAR and not relying so much on a depicted FMS vertical profile. Being relatively new to the airplane; I am still intently watching the automation to further my understanding of its capabilities and limitations but that can't be done at the expense of the basics.
EMB-175 First Officer reported overshooting a crossing restriction on arrival to LAX.